poj 1493 Machined Surfaces

#include <iostream>#include <cstdio>#include <cstdlib>#include <cstring>using namespace std;#define maxn 20int f[maxn];int n, ans;void input(){    ans = 0;    getchar();    for (int i = 0; i < n; i++)    {        f[i] = 0;        for (int j = 0; j < 25; j++)        { char ch = getchar(); if (ch == 'X')     f[i]++;        }        ans = max(ans, f[i]);        getchar();    }}int main(){    while (scanf("%d", &n), n)    {        input();        int d = 0;        for (int i = 0; i < n; i++) d += ans - f[i];        printf("%dn", d);    }    return 0;}