C program to check whether one string is permutation of another string

Write a program to find whether two given strings are permutations of each other.  A string str1 is a permutation of str2 if all the characters in str1 appear the same number of times in str2 and str2 is of the same length as str1.

Input: Two strings S1 and S2

Output: yes - if they satisfy given criteria

no - otherwise

Constraints:

1 <= len(S1), len(S2) <= 100.

Characters from ASCII range 0 to 127.

White space will not be given in the string.

Implementation:

#include <stdio.h> #include <stdlib.h> #include <string.h> #define MAX 101 int length(char *s) { int len=0; while(*s) len++,s++; return len; } int compare(int *s,int *v) { int i; for(i=0;i<26;i++) if(s[i]!=v[i]) return 0; return 1; } int main() { char *s,*v; int shash[26],vhash[26]; int i; s=(char*)malloc(sizeof(char)*MAX); v=(char*)malloc(sizeof(char)*MAX); memset(shash,0,sizeof(shash)); memset(vhash,0,sizeof(vhash)); scanf("%s",s); scanf("%s",v); if(length(s)==length(v)) { i=0; while(s[i]) { shash[s[i]-'a']++; i++; } i=0; while(v[i]) { vhash[v[i]-'a']++; i++; } if(compare(shash,vhash)) printf("yes"); else printf("no"); } else { printf("no"); } return 0; }