{"id":26495,"date":"2017-12-20T21:25:11","date_gmt":"2017-12-20T15:55:11","guid":{"rendered":"https:\/\/www.wikitechy.com\/technology\/?p=26495"},"modified":"2017-12-20T21:25:11","modified_gmt":"2017-12-20T15:55:11","slug":"c-programming-backtracking-hamiltonian-cycle","status":"publish","type":"post","link":"https:\/\/www.wikitechy.com\/technology\/c-programming-backtracking-hamiltonian-cycle\/","title":{"rendered":"C Programming &#8211; Backtracking | Set 6 (Hamiltonian Cycle)"},"content":{"rendered":"<p><a href=\"http:\/\/en.wikipedia.org\/wiki\/Hamiltonian_path\" target=\"_blank\" rel=\"noopener\">Hamiltonian Path<\/a> in an undirected graph is a path that visits each vertex exactly once. A Hamiltonian cycle (or Hamiltonian circuit) is a Hamiltonian Path such that there is an edge (in graph) from the last vertex to the first vertex of the Hamiltonian Path.<span id=\"more-19092\"><\/span> Determine whether a given graph contains Hamiltonian Cycle or not. If it contains, then print the path. Following are the input and output of the required function.<\/p>\n<p><em>Input:<\/em><br \/>\nA 2D array graph[V][V] where V is the number of vertices in graph and graph[V][V] is adjacency matrix representation of the graph. A value graph[i][j] is 1 if there is a direct edge from i to j, otherwise graph[i][j] is 0.<\/p>\n<p><em>Output:<\/em><br \/>\nAn array path[V] that should contain the Hamiltonian Path. path[i] should represent the ith vertex in the Hamiltonian Path. The code should also return false if there is no Hamiltonian Cycle in the graph.<\/p>\n[ad type=&#8221;banner&#8221;]\n<p>For example, a Hamiltonian Cycle in the following graph is {0, 1, 2, 4, 3, 0}. There are more Hamiltonian Cycles in the graph like {0, 3, 4, 2, 1, 0}<\/p>\n<pre>(0)--(1)--(2)\r\n |   \/ \\   |\r\n |  \/   \\  | \r\n | \/     \\ |\r\n(3)-------(4)\r\n<\/pre>\n<p>And the following graph doesn\u2019t contain any Hamiltonian Cycle.<\/p>\n<pre>(0)--(1)--(2)\r\n |   \/ \\   |\r\n |  \/   \\  | \r\n | \/     \\ |\r\n(3)      (4) \r\n<\/pre>\n<div id=\"practice\">\n<h2 id=\"recommended-please-solve-it-on-practice-first-before-moving-on-to-the-solution\"><a href=\"http:\/\/practice.geeksforgeeks.org\/problems\/hamiltonian-path\/0\" target=\"_blank\" rel=\"noopener\">Recommended: Please solve it on &#8220;<b><i><u>PRACTICE<\/u><\/i><\/b>&#8221; first, before moving on to the solution.<\/a><\/h2>\n<\/div>\n<p><strong>Naive Algorithm<\/strong><br \/>\nGenerate all possible configurations of vertices and print a configuration that satisfies the given constraints. There will be n! (n factorial) configurations.<\/p>\n<pre>while there are untried conflagrations\r\n{\r\n   generate the next configuration\r\n   if ( there are edges between two consecutive vertices of this\r\n      configuration and there is an edge from the last vertex to \r\n      the first ).\r\n   {\r\n      print this configuration;\r\n      break;\r\n   }\r\n}\r\n<\/pre>\n<p><strong>Backtracking Algorithm<\/strong><br \/>\nCreate an empty path array and add vertex 0 to it. Add other vertices, starting from the vertex 1. Before adding a vertex, check for whether it is adjacent to the previously added vertex and not already added. If we find such a vertex, we add the vertex as part of the solution. If we do not find a vertex then we return false.<\/p>\n[ad type=&#8221;banner&#8221;]\n<p><strong>Implementation of Backtracking solution<\/strong><br \/>\nFollowing are implementations of the Backtracking solution.<\/p>\n<p><strong>C++ program:<\/strong><\/p>\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"c comments\">\/* C\/C++ program for solution of Hamiltonian Cycle problem<\/code><\/div>\n<div class=\"line number2 index1 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">using backtracking *\/<\/code><\/div>\n<div class=\"line number3 index2 alt2\"><code class=\"c preprocessor\">#include&lt;stdio.h&gt;<\/code><\/div>\n<div class=\"line number4 index3 alt1\"><\/div>\n<div class=\"line number5 index4 alt2\"><code class=\"c comments\">\/\/ Number of vertices in the graph<\/code><\/div>\n<div class=\"line number6 index5 alt1\"><code class=\"c preprocessor\">#define V 5<\/code><\/div>\n<div class=\"line number7 index6 alt2\"><\/div>\n<div class=\"line number8 index7 alt1\"><code class=\"c keyword bold\">void<\/code> <code class=\"c plain\">printSolution(<\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">path[]);<\/code><\/div>\n<div class=\"line number9 index8 alt2\"><\/div>\n<div class=\"line number10 index9 alt1 highlighted\"><code class=\"c comments\">\/* A utility function to check if the vertex v can be added at<\/code><\/div>\n<div class=\"line number11 index10 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">index 'pos' in the Hamiltonian Cycle constructed so far (stored<\/code><\/div>\n<div class=\"line number12 index11 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">in 'path[]') *\/<\/code><\/div>\n<div class=\"line number13 index12 alt2 highlighted\"><code class=\"c color1 bold\">bool<\/code> <code class=\"c plain\">isSafe(<\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">v, <\/code><code class=\"c color1 bold\">bool<\/code> <code class=\"c plain\">graph[V][V], <\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">path[], <\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">pos)<\/code><\/div>\n<div class=\"line number14 index13 alt1 highlighted\"><code class=\"c plain\">{<\/code><\/div>\n<div class=\"line number15 index14 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/* Check if this vertex is an adjacent vertex of the previously<\/code><\/div>\n<div class=\"line number16 index15 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">added vertex. *\/<\/code><\/div>\n<div class=\"line number17 index16 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">if<\/code> <code class=\"c plain\">(graph [ path[pos-1] ][ v ] == 0)<\/code><\/div>\n<div class=\"line number18 index17 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">return<\/code> <code class=\"c keyword bold\">false<\/code><code class=\"c plain\">;<\/code><\/div>\n<div class=\"line number19 index18 alt2 highlighted\"><\/div>\n<div class=\"line number20 index19 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/* Check if the vertex has already been included.<\/code><\/div>\n<div class=\"line number21 index20 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">This step can be optimized by creating an array of size V *\/<\/code><\/div>\n<div class=\"line number22 index21 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">for<\/code> <code class=\"c plain\">(<\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">i = 0; i &lt; pos; i++)<\/code><\/div>\n<div class=\"line number23 index22 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">if<\/code> <code class=\"c plain\">(path[i] == v)<\/code><\/div>\n<div class=\"line number24 index23 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">return<\/code> <code class=\"c keyword bold\">false<\/code><code class=\"c plain\">;<\/code><\/div>\n<div class=\"line number25 index24 alt2 highlighted\"><\/div>\n<div class=\"line number26 index25 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">return<\/code> <code class=\"c keyword bold\">true<\/code><code class=\"c plain\">;<\/code><\/div>\n<div class=\"line number27 index26 alt2 highlighted\"><code class=\"c plain\">}<\/code><\/div>\n<div class=\"line number28 index27 alt1 highlighted\"><\/div>\n<div class=\"line number29 index28 alt2 highlighted\"><code class=\"c comments\">\/* A recursive utility function to solve hamiltonian cycle problem *\/<\/code><\/div>\n<div class=\"line number30 index29 alt1 highlighted\"><code class=\"c color1 bold\">bool<\/code> <code class=\"c plain\">hamCycleUtil(<\/code><code class=\"c color1 bold\">bool<\/code> <code class=\"c plain\">graph[V][V], <\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">path[], <\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">pos)<\/code><\/div>\n<div class=\"line number31 index30 alt2 highlighted\"><code class=\"c plain\">{<\/code><\/div>\n<div class=\"line number32 index31 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/* base case: If all vertices are included in Hamiltonian Cycle *\/<\/code><\/div>\n<div class=\"line number33 index32 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">if<\/code> <code class=\"c plain\">(pos == V)<\/code><\/div>\n<div class=\"line number34 index33 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{<\/code><\/div>\n<div class=\"line number35 index34 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/\/ And if there is an edge from the last included vertex to the<\/code><\/div>\n<div class=\"line number36 index35 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/\/ first vertex<\/code><\/div>\n<div class=\"line number37 index36 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">if<\/code> <code class=\"c plain\">( graph[ path[pos-1] ][ path[0] ] == 1 )<\/code><\/div>\n<div class=\"line number38 index37 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">return<\/code> <code class=\"c keyword bold\">true<\/code><code class=\"c plain\">;<\/code><\/div>\n<div class=\"line number39 index38 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">else<\/code><\/div>\n<div class=\"line number40 index39 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">return<\/code> <code class=\"c keyword bold\">false<\/code><code class=\"c plain\">;<\/code><\/div>\n<div class=\"line number41 index40 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">}<\/code><\/div>\n<div class=\"line number42 index41 alt1 highlighted\"><\/div>\n<div class=\"line number43 index42 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/\/ Try different vertices as a next candidate in Hamiltonian Cycle.<\/code><\/div>\n<div class=\"line number44 index43 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/\/ We don't try for 0 as we included 0 as starting point in in hamCycle()<\/code><\/div>\n<div class=\"line number45 index44 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">for<\/code> <code class=\"c plain\">(<\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">v = 1; v &lt; V; v++)<\/code><\/div>\n<div class=\"line number46 index45 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{<\/code><\/div>\n<div class=\"line number47 index46 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/* Check if this vertex can be added to Hamiltonian Cycle *\/<\/code><\/div>\n<div class=\"line number48 index47 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">if<\/code> <code class=\"c plain\">(isSafe(v, graph, path, pos))<\/code><\/div>\n<div class=\"line number49 index48 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{<\/code><\/div>\n<div class=\"line number50 index49 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">path[pos] = v;<\/code><\/div>\n<div class=\"line number51 index50 alt2 highlighted\"><\/div>\n<div class=\"line number52 index51 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/* recur to construct rest of the path *\/<\/code><\/div>\n<div class=\"line number53 index52 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">if<\/code> <code class=\"c plain\">(hamCycleUtil (graph, path, pos+1) == <\/code><code class=\"c keyword bold\">true<\/code><code class=\"c plain\">)<\/code><\/div>\n<div class=\"line number54 index53 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">return<\/code> <code class=\"c keyword bold\">true<\/code><code class=\"c plain\">;<\/code><\/div>\n<div class=\"line number55 index54 alt2 highlighted\"><\/div>\n<div class=\"line number56 index55 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/* If adding vertex v doesn't lead to a solution,<\/code><\/div>\n<div class=\"line number57 index56 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">then remove it *\/<\/code><\/div>\n<div class=\"line number58 index57 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">path[pos] = -1;<\/code><\/div>\n<div class=\"line number59 index58 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">}<\/code><\/div>\n<div class=\"line number60 index59 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">}<\/code><\/div>\n<div class=\"line number61 index60 alt2 highlighted\"><\/div>\n<div class=\"line number62 index61 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/* If no vertex can be added to Hamiltonian Cycle constructed so far,<\/code><\/div>\n<div class=\"line number63 index62 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">then return false *\/<\/code><\/div>\n<div class=\"line number64 index63 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">return<\/code> <code class=\"c keyword bold\">false<\/code><code class=\"c plain\">;<\/code><\/div>\n<div class=\"line number65 index64 alt2 highlighted\"><code class=\"c plain\">}<\/code><\/div>\n<div class=\"line number66 index65 alt1 highlighted\"><\/div>\n<div class=\"line number67 index66 alt2 highlighted\"><code class=\"c comments\">\/* This function solves the Hamiltonian Cycle problem using Backtracking.<\/code><\/div>\n<div class=\"line number68 index67 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0<\/code><code class=\"c comments\">It mainly uses hamCycleUtil() to solve the problem. It returns false<\/code><\/div>\n<div class=\"line number69 index68 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0<\/code><code class=\"c comments\">if there is no Hamiltonian Cycle possible, otherwise return true and<\/code><\/div>\n<div class=\"line number70 index69 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0<\/code><code class=\"c comments\">prints the path. Please note that there may be more than one solutions,<\/code><\/div>\n<div class=\"line number71 index70 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0<\/code><code class=\"c comments\">this function prints one of the feasible solutions. *\/<\/code><\/div>\n<div class=\"line number72 index71 alt1 highlighted\"><code class=\"c color1 bold\">bool<\/code> <code class=\"c plain\">hamCycle(<\/code><code class=\"c color1 bold\">bool<\/code> <code class=\"c plain\">graph[V][V])<\/code><\/div>\n<div class=\"line number73 index72 alt2 highlighted\"><code class=\"c plain\">{<\/code><\/div>\n<div class=\"line number74 index73 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">*path = <\/code><code class=\"c keyword bold\">new<\/code> <code class=\"c color1 bold\">int<\/code><code class=\"c plain\">[V];<\/code><\/div>\n<div class=\"line number75 index74 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">for<\/code> <code class=\"c plain\">(<\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">i = 0; i &lt; V; i++)<\/code><\/div>\n<div class=\"line number76 index75 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">path[i] = -1;<\/code><\/div>\n<div class=\"line number77 index76 alt2 highlighted\"><\/div>\n<div class=\"line number78 index77 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/* Let us put vertex 0 as the first vertex in the path. If there is<\/code><\/div>\n<div class=\"line number79 index78 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">a Hamiltonian Cycle, then the path can be started from any point<\/code><\/div>\n<div class=\"line number80 index79 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">of the cycle as the graph is undirected *\/<\/code><\/div>\n<div class=\"line number81 index80 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">path[0] = 0;<\/code><\/div>\n<div class=\"line number82 index81 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">if<\/code> <code class=\"c plain\">( hamCycleUtil(graph, path, 1) == <\/code><code class=\"c keyword bold\">false<\/code> <code class=\"c plain\">)<\/code><\/div>\n<div class=\"line number83 index82 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{<\/code><\/div>\n<div class=\"line number84 index83 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c functions bold\">printf<\/code><code class=\"c plain\">(<\/code><code class=\"c string\">\"\\nSolution does not exist\"<\/code><code class=\"c plain\">);<\/code><\/div>\n<div class=\"line number85 index84 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">return<\/code> <code class=\"c keyword bold\">false<\/code><code class=\"c plain\">;<\/code><\/div>\n<div class=\"line number86 index85 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">}<\/code><\/div>\n<div class=\"line number87 index86 alt2 highlighted\"><\/div>\n<div class=\"line number88 index87 alt1 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">printSolution(path);<\/code><\/div>\n<div class=\"line number89 index88 alt2 highlighted\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">return<\/code> <code class=\"c keyword bold\">true<\/code><code class=\"c plain\">;<\/code><\/div>\n<div class=\"line number90 index89 alt1 highlighted\"><code class=\"c plain\">}<\/code><\/div>\n<div class=\"line number91 index90 alt2\"><\/div>\n<div class=\"line number92 index91 alt1\"><code class=\"c comments\">\/* A utility function to print solution *\/<\/code><\/div>\n<div class=\"line number93 index92 alt2\"><code class=\"c keyword bold\">void<\/code> <code class=\"c plain\">printSolution(<\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">path[])<\/code><\/div>\n<div class=\"line number94 index93 alt1\"><code class=\"c plain\">{<\/code><\/div>\n<div class=\"line number95 index94 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c functions bold\">printf<\/code> <code class=\"c plain\">(<\/code><code class=\"c string\">\"Solution Exists:\"<\/code><\/div>\n<div class=\"line number96 index95 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c string\">\" Following is one Hamiltonian Cycle \\n\"<\/code><code class=\"c plain\">);<\/code><\/div>\n<div class=\"line number97 index96 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">for<\/code> <code class=\"c plain\">(<\/code><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">i = 0; i &lt; V; i++)<\/code><\/div>\n<div class=\"line number98 index97 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c functions bold\">printf<\/code><code class=\"c plain\">(<\/code><code class=\"c string\">\" %d \"<\/code><code class=\"c plain\">, path[i]);<\/code><\/div>\n<div class=\"line number99 index98 alt2\"><\/div>\n<div class=\"line number100 index99 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/\/ Let us print the first vertex again to show the complete cycle<\/code><\/div>\n<div class=\"line number101 index100 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c functions bold\">printf<\/code><code class=\"c plain\">(<\/code><code class=\"c string\">\" %d \"<\/code><code class=\"c plain\">, path[0]);<\/code><\/div>\n<div class=\"line number102 index101 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c functions bold\">printf<\/code><code class=\"c plain\">(<\/code><code class=\"c string\">\"\\n\"<\/code><code class=\"c plain\">);<\/code><\/div>\n<div class=\"line number103 index102 alt2\"><code class=\"c plain\">}<\/code><\/div>\n<div class=\"line number104 index103 alt1\"><\/div>\n<div class=\"line number105 index104 alt2\"><code class=\"c comments\">\/\/ driver program to test above function<\/code><\/div>\n<div class=\"line number106 index105 alt1\"><code class=\"c color1 bold\">int<\/code> <code class=\"c plain\">main()<\/code><\/div>\n<div class=\"line number107 index106 alt2\"><code class=\"c plain\">{<\/code><\/div>\n<div class=\"line number108 index107 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/* Let us create the following graph<\/code><\/div>\n<div class=\"line number109 index108 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">(0)--(1)--(2)<\/code><\/div>\n<div class=\"line number110 index109 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">|\u00a0\u00a0 \/ \\\u00a0\u00a0 |<\/code><\/div>\n<div class=\"line number111 index110 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">|\u00a0 \/\u00a0\u00a0 \\\u00a0 |<\/code><\/div>\n<div class=\"line number112 index111 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">| \/\u00a0\u00a0\u00a0\u00a0 \\ |<\/code><\/div>\n<div class=\"line number113 index112 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">(3)-------(4)\u00a0\u00a0\u00a0 *\/<\/code><\/div>\n<div class=\"line number114 index113 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0<\/code><code class=\"c color1 bold\">bool<\/code> <code class=\"c plain\">graph1[V][V] = {{0, 1, 0, 1, 0},<\/code><\/div>\n<div class=\"line number115 index114 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{1, 0, 1, 1, 1},<\/code><\/div>\n<div class=\"line number116 index115 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{0, 1, 0, 0, 1},<\/code><\/div>\n<div class=\"line number117 index116 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{1, 1, 0, 0, 1},<\/code><\/div>\n<div class=\"line number118 index117 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{0, 1, 1, 1, 0},<\/code><\/div>\n<div class=\"line number119 index118 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">};<\/code><\/div>\n<div class=\"line number120 index119 alt1\"><\/div>\n<div class=\"line number121 index120 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/\/ Print the solution<\/code><\/div>\n<div class=\"line number122 index121 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">hamCycle(graph1);<\/code><\/div>\n<div class=\"line number123 index122 alt2\"><\/div>\n<div class=\"line number124 index123 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/* Let us create the following graph<\/code><\/div>\n<div class=\"line number125 index124 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">(0)--(1)--(2)<\/code><\/div>\n<div class=\"line number126 index125 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">|\u00a0\u00a0 \/ \\\u00a0\u00a0 |<\/code><\/div>\n<div class=\"line number127 index126 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">|\u00a0 \/\u00a0\u00a0 \\\u00a0 |<\/code><\/div>\n<div class=\"line number128 index127 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">| \/\u00a0\u00a0\u00a0\u00a0 \\ |<\/code><\/div>\n<div class=\"line number129 index128 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">(3)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 (4)\u00a0\u00a0\u00a0 *\/<\/code><\/div>\n<div class=\"line number130 index129 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c color1 bold\">bool<\/code> <code class=\"c plain\">graph2[V][V] = {{0, 1, 0, 1, 0},<\/code><\/div>\n<div class=\"line number131 index130 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{1, 0, 1, 1, 1},<\/code><\/div>\n<div class=\"line number132 index131 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{0, 1, 0, 0, 1},<\/code><\/div>\n<div class=\"line number133 index132 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{1, 1, 0, 0, 0},<\/code><\/div>\n<div class=\"line number134 index133 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">{0, 1, 1, 0, 0},<\/code><\/div>\n<div class=\"line number135 index134 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">};<\/code><\/div>\n<div class=\"line number136 index135 alt1\"><\/div>\n<div class=\"line number137 index136 alt2\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c comments\">\/\/ Print the solution<\/code><\/div>\n<div class=\"line number138 index137 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c plain\">hamCycle(graph2);<\/code><\/div>\n<div class=\"line number139 index138 alt2\"><\/div>\n<div class=\"line number140 index139 alt1\"><code class=\"c spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"c keyword bold\">return<\/code> <code class=\"c plain\">0;<\/code><\/div>\n<div class=\"line number141 index140 alt2\"><code class=\"c plain\">}<\/code><\/div>\n<div class=\"line number141 index140 alt2\">\n<p>Output:<\/p>\n<pre>Solution Exists: Following is one Hamiltonian Cycle\r\n 0  1  2  4  3  0\r\n\r\nSolution does not exist\r\n<\/pre>\n<\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n[ad type=&#8221;banner&#8221;]\n","protected":false},"excerpt":{"rendered":"<p>C Programming &#8211; Backtracking &#8211; Hamiltonian Cycle &#8211; Create an empty path array and add vertex 0 to it. Add other vertices, starting from the vertex 1<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[73904,69866,1,73906,78521],"tags":[78964,75506,78968,78963,78966,78965,78967],"class_list":["post-26495","post","type-post","status-publish","format-standard","hentry","category-backtracking","category-c-programming","category-coding","category-graph-algorithms","category-hard-problems","tag-hamiltonian-circuit-problem-algorithm","tag-hamiltonian-cycle-algorithm-using-backtracking-in-c","tag-hamiltonian-cycle-algorithm-using-backtracking-pdf","tag-hamiltonian-cycle-algorithm-using-backtracking-ppt","tag-hamiltonian-cycle-algorithm-using-backtracking-time-complexity","tag-hamiltonian-cycle-example","tag-hamiltonian-path-algorithm-pseudocode"],"_links":{"self":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts\/26495","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/comments?post=26495"}],"version-history":[{"count":0,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts\/26495\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/media?parent=26495"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/categories?post=26495"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/tags?post=26495"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}