Permuting a String.

Write a C program to print all permutations of a given string ?

For Ex: The Permutation of string "ABC" are "ABC, ACB, BAC, BCA, CAB, CBA"

Program: (using backtracking)

# include <stdio.h>

# include <conio.h>

void swap (char *x, char *y)

{

    char temp;

    temp = *x;

    *x = *y;

    *y = temp;

}

void permute(char *a, int i, int n)

{

   int j;

   if (i == n)

     printf("%s\n", a);

   else

   {

for (j = i; j <= n; j++)

       {

 swap((a+i), (a+j));

 permute(a, i+1, n);

 swap((a+i), (a+j)); //backtrack

       }

   }

}

void main()

{

   char a[] = "ABC";

   clrscr();

   permute(a, 0, 2);

   getch();

}