uva 1368

简单的贪心 ~ 

#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <map>
#include <set>
#include <stack>
#include <vector>
#include <sstream>
#include <string>
#include <cstring>
#include <algorithm>
#include <iostream>
#define maxn 1010
#define INF 0x7fffffff
#define inf 10000000
#define MOD 1000000007
#define ull unsigned long long
#define ll long long
using namespace std;

char dna[55][maxn], ans[maxn];
int n, m, num[100], sum;
void solve()
{
    sum = 0;
    for(int i = 0; i < n; ++ i)
    {
        memset(num, 0, sizeof(num));
        int _max = 0, now;
        for(int j = 0; j < m; ++ j)
        {
            int tem = dna[j][i] - 'A';
            num[tem] ++;
            if(num[tem] > _max)
            {
                _max = num[tem];
                now = tem;
            }
            else if(num[tem] == _max && tem < now) now = tem;
        }
        ans[i] = now+'A';
        sum += m-_max;
    }
    ans[n] = '\0';
}

int main()
{
    int t;
    scanf("%d", &t);
    while(t --)
    {
        scanf("%d%d", &m, &n);
        for(int i = 0 ; i < m; ++ i) scanf("%s", dna[i]);
        solve();
        puts(ans);
        printf("%d\n", sum);
    }
    return 0;
}