c - WA in CPRMT(common permutation) -

#include<stdio.h>  void compare(char a[], char b[]); void sort(char a[], char b[], char c[], int k); int main() {  char a[1001], b[1001]; while((scanf("%s%s", a,b))!=eof) {     compare(a, b); } return 0; }    void compare(char a[], char b[]) { int i,j,k,l,m; i=0;k=0;j=0; char c[1001]; while(a[i]!='\0') {     while(b[j]!='\0')     {         l=a[i];         m=b[j];         if(l==m)         {             c[k]=a[i];             k++;         }         j++;     }     i++;     j=0; } c[k]='\0'; sort(a,b,c,k);  }  void sort(char a[], char b[], char c[], int k) { int i,m,n,j,o,p,h,l[k]; for(i=0;i<=k;i++) {     l[i]=c[i]; } for(i=0;i<k;i++) {     for(j=0;j<k-1;j++)     {         if(l[j]>l[j+1])         {             m=l[j];             l[j]=l[j+1];             l[j+1]=m;             c[j]=l[j];             c[j+1]=l[j+1];         }     } } i=0; while(l[i+1]!='\0') {     if(l[i]==l[i+1])     {         m=0;         n=0;         j=0;         while(a[j]!='\0')         {             if(a[j]==l[i])             {                 m=m+1;             }             j++;         }         j=0;         while(b[j]!='\0')         {             if(b[j]==l[i])             {                 n=n+1;             }             j++;         }         if(m<=n)         {             h=m;          }         else         {             h=n;         }         o=m*n;         p=0;         while(c[i+p+h]!='\0')         {             c[i+p+h]=c[i+p+o];             l[i+p+h]=l[i+p+o];             p++;         }     }     i++; } printf("%s\n", c); } 

i still getting wa question...can sugggest me more test cases.... have tried following test cases input pretty women walking down street test totter

and output is- e nw et ett

i think skipping test cases........if know more test cases please let me know..