Hdu 4496

题目链接

并查集简单题，赛前复习 :.....

附上代码：

 1 /*************************************************************************  2  > File Name: 4496.cpp  3  > Author: Stomach_ache  4  > Mail: [email protected]  5  > Created Time: 2014年05月19日 星期一 23时51分28秒  6  > Propose:  7  ************************************************************************/

 8 

 9 #include <cmath>

10 #include <string>

11 #include <cstdio>

12 #include <fstream>

13 #include <cstring>

14 #include <iostream>

15 #include <algorithm>

16 using namespace std; 17 

18 typedef pair<int, int> pii; 19 pii a[100005]; 20 int ans[100005], fa[10005]; 21 

22 int

23 findSet(int x) { 24       return fa[x] != x ? fa[x]=findSet(fa[x]) : x; 25 } 26 

27 int

28 main(void) { 29       int n, m; 30       while (scanf("%d %d", &n, &m) == 2) { 31          for (int i = 0; i < n; i++) { 32               fa[i] = i; 33  } 34         for (int i = 0; i < m; i++) { 35             scanf("%d %d", &a[i].first, &a[i].second); 36  } 37         ans[m] = n; 38         for (int i = m-1; i > 0; i--) { 39               int x = findSet(a[i].first); 40             int y = findSet(a[i].second); 41               if (x != y) { 42                 fa[x] = y; 43                 ans[i] = ans[i+1] - 1; 44             } else { 45                   ans[i] = ans[i+1]; 46  } 47  } 48         for (int i = 1; i <= m; i++) { 49               printf("%d\n", ans[i]); 50  } 51  } 52 

53     return 0; 54 }