C Programming for Efficient way to multiply with 7

# include<stdio.h>
 
int multiplyBySeven(unsigned int n)
{  
    /* Note the inner bracket here. This is needed 
       because precedence of '-' operator is higher 
       than '<<' */
    return ((n<<3) - n);
}
 
/* Driver program to test above function */
int main()
{
    unsigned int n = 4;
    printf("%u", multiplyBySeven(n));
 
    getchar();
    return 0;
}