BZOJ1854 [Scoi2010]游戏

首先吐槽一下这什么破游戏啊。。。

网上的做法都是跑二分图匹配，当我知道有并查集做法的时候眼瞎了。。。

Orz BLADEVIL （←看这个题解吧。。。）

 

 1 /**************************************************************
 2     Problem: 1854
 3     User: rausen
 4     Language: C++
 5     Result: Accepted
 6     Time:760 ms
 7     Memory:5688 kb
 8 ****************************************************************/
 9  
10 #include <cstdio>
11 #include <algorithm>
12  
13 using namespace std;
14 const int N = 1000001;
15 int n, fa[N];
16 bool vis[N];
17  
18 inline int read(){
19     int x = 0;
20     char ch = getchar();
21     while (ch < '0' || ch > '9')
22         ch = getchar();
23     while (ch >= '0' && ch <= '9'){
24         x = x * 10 + ch - '0';
25         ch = getchar();
26     }
27     return x;
28 }
29  
30 int find_fa(int x){
31     return x == fa[x] ? x : fa[x] = find_fa(fa[x]);
32 }
33  
34 inline void Union(int x, int y){
35     if (x < y) swap(x, y);
36     vis[y] = 1;
37     fa[y] = x;
38 }
39  
40 int main(){
41     n = read();
42     int i, x, y;
43     for (i = 1; i <= n + 1; ++i)
44         fa[i] = i;
45     for (i = 1; i <= n; ++i){
46         x = read(), x = find_fa(x);
47         y = read(), y = find_fa(y);
48         if (x == y) vis[x] = 1;
49         else Union(x, y);
50     }
51     for (i = 1; i <= n + 1; ++i)
52         if (!vis[i]){
53             printf("%d\n", i - 1);
54             break;
55         }
56     return 0;
57 }
View Code

 

posted on 2014-10-31 16:35  Xs酱~  阅读(202)  评论(0)  编辑  收藏  举报