Word Morphing

#include<bits/stdc++.h>

using namespace std;

struct data
{
    int counter;

    int index;

} ans[1003];

char store[1003][1003];

bool cmp(data l,data r)
{
    return l.counter<r.counter;
}

int main()
{
    int koyta,len,i,j,counter;

    while(scanf("%d%d",&koyta,&len)==2)
    {
        for(i=1; i<=koyta; i++)
        {
            scanf("%s",store[i]);
        }

        for(i=1; i<=koyta; i++)
        {
            counter = 0;

            for(j=0; j<len; j++)
            {
                counter += (store[1][j]!=store[i][j]);
            }

            ans[i].counter = counter;

            ans[i].index = i;
        }

        sort(ans+1,ans+koyta+1,cmp);

        for(i=1; i<=koyta; i++)
        {
            printf("%s\n",store[ans[i].index]);
        }
    }

    return 0;
}