Question

How to generate all possible permutations of a string in C

Answer 1

#include <stdio.h>
#include <string.h>
 
void swap(char *si, char *sj) {
 
    char temp;
 
    temp = *si;
    *si = *sj;
    *sj = temp;
}
 
void print_permutations(char *s, int i, int len) {
   if (i == len)
       printf("%s\n", s);
   else {
        for (int j = i; j <= len; j++) {
            swap((s + i), (s + j));
            print_permutations(s, i + 1, len);
            swap((s + i), (s + j));
       }
   }
} 
 
int main(void) {
   char s[10] = "abcd";
 
   print_permutations(s, 0, strlen(s) - 1);
 
   return 0;
 
}
 
 
 
/*
run:
 
abcd
abdc
acbd
acdb
adcb
adbc
bacd
badc
bcad
bcda
bdca
bdac
cbad
cbda
cabd
cadb
cdab
cdba
dbca
dbac
dcba
dcab
dacb
dabc
 
*/

 

70+ SQL courses for beginners and professionals