找规律/贪心 Codeforces Round #310 (Div. 2) A. Case of the Zeros and Ones

 1 /*
 2     找规律/贪心：ans = n - 01匹配的总数，水
 3 */
 4 #include <cstdio>
 5 #include <iostream>
 6 #include <algorithm>
 7 #include <cstring>
 8 #include <cmath>
 9 using namespace std;
10 
11 const int MAXN = 2e5 + 10;
12 const int INF = 0x3f3f3f3f;
13 char s[MAXN];
14 
15 int main(void)        //Codeforces Round #310 (Div. 2) A. Case of the Zeros and Ones
16 {
17     // freopen ("A.in", "r", stdin);
18 
19     int n;
20     while (scanf ("%d", &n) == 1)
21     {
22         scanf ("%s", s);
23         int cnt_0 = 0, cnt_1 = 0;
24         for (int i=0; i<n; ++i)
25         {
26             if (s[i] == ‘0‘)    cnt_0++;
27             else    cnt_1++;
28         }
29 
30         printf ("%d\n", n - min (cnt_0, cnt_1) * 2);
31     }
32 
33 
34     return 0;
35 }