[CF837B] Flag of Berland（乱写）

题意：http://codeforces.com/contest/837/problem/B

判断给定二维阵是否是个条形旗，条形旗符合条件：

• Flag consists of three colors which correspond to letters 'R', 'G' and 'B'.
• Flag consists of three equal in width and height stripes, parralel to each other and to sides of the flag. Each stripe has exactly one color.
• Each color should be used in exactly one stripe.

没什么特别的，就是想记录一下骚操作。。

#include <bits/stdc++.h>
using namespace std;

const int maxn = 110;
int n, m;
char a[maxn][maxn], b[maxn][maxn];
int vis[256];

bool ok() {
    return
        (!vis['R'] && !vis['G'] && vis['B']) ||
        (!vis['R'] && vis['G'] && !vis['B']) ||
        (vis['R'] && !vis['G'] && !vis['B']);
}

signed main() {
    // freopen("in", "r", stdin);
    while(~scanf("%d%d",&n,&m)) {
        memset(a, 0, sizeof(a));
        memset(b, 0, sizeof(b));
        memset(vis, 0, sizeof(vis));
        for(int i = 0; i < n; i++) scanf("%s", a[i]);
        for(int i = 0; i < n; i++) {
            for(int j = 0; j < m; j++) {
                b[j][i] = a[i][j];
                vis[a[i][j]]++;
            }
        }
        if(!(vis['R'] == vis['G'] && vis['G'] == vis['B'])) {
            puts("NO");
            continue;
        }
        bool ok1 = 1, ok2 = 1;
        for(int i = 0; i < n; i++) {
            bool t1 = 1;
            memset(vis, 0, sizeof(vis));
            for(int j = 0; j < m; j++) vis[a[i][j]]++;
            if(!ok()) t1 = 0;
            if(!t1) ok1 = 0;
        }
        for(int i = 0; i < m; i++) {
            bool t2 = 1;
            memset(vis, 0, sizeof(vis));
            for(int j = 0; j < n; j++) vis[b[i][j]]++;
            if(!ok()) t2 = 0;
            if(!t2) ok2 = 0;
        }
        ok1 &= ((unique(b[0], b[0]+n) - b[0]) == 3);
        ok2 &= ((unique(a[0], a[0]+m) - a[0]) == 3);
        if(ok1 || ok2) puts("YES");
        else puts("NO");
    }
    return 0;
}