贪心 Codeforces Round #309 (Div. 2) B. Ohana Cleans Up

 1 /*
 2     题意：某几列的数字翻转，使得某些行全为1，求出最多能有几行
 3     想了好久都没有思路，看了代码才知道不用蠢办法，匹配初始相同的行最多能有几对就好了，不必翻转
 4 */
 5 #include <cstdio>
 6 #include <algorithm>
 7 #include <string>
 8 #include <cmath>
 9 #include <iostream>
10 using namespace std;
11 
12 const int MAXN = 1e2 + 10;
13 const int INF = 0x3f3f3f3f;
14 string s[MAXN];
15 
16 int main(void)        //Codeforces Round #309 (Div. 2) B. Ohana Cleans Up
17 {
18 //    freopen ("B.in", "r", stdin);
19 
20     int n;
21     while (scanf ("%d", &n) == 1)
22     {
23         for (int i=1; i<=n; ++i)    cin >> s[i];
24         int ans = 0;
25         for (int i=1; i<=n; ++i)
26         {
27             int m = 0;
28             for (int j=1; j<=n; ++j)
29             {
30                 if (s[i] == s[j])    m++;
31             }
32             ans = max (ans, m);
33         }
34 
35         printf ("%d\n", ans);
36     }
37 
38     return 0;
39 }