POJ2524 Ubiquitous Religions(并查集)

来源：互联网发布：和父母关系不好知乎编辑：程序博客网时间：2024/05/22 03:21

题意：

学校中每个人都有宗教信仰，现在只能知道某些人的宗教信仰相同，求总共有几种宗教

要点：

水题，跟HDU1213一毛一样，都是求最后集合个数，早知道不做了

15315712Seasonal2524Accepted504K313MSC++691B2016-03-26 12:24:55

#include<stdio.h>#include<string.h>#include<stdlib.h>#define maxn 50050int p[maxn], rank[maxn];int m, n,num;void init(){for (int i = 1; i <= m; i++){p[i] = i;rank[i] = 0;}}int find(int x){if (p[x] == x) return x;return p[x] = find(p[x]);}void merge(int x, int y){x = find(x);y = find(y);if (x == y) return;if (rank[x] > rank[y]){p[y] = x;num--;}else{p[x] = y;if (rank[x] == rank[y]) rank[y]++;num--;}}int main(){int kase = 1, x, y;while (~scanf("%d%d", &m, &n), n + m){init();//初始化不能忘记num = m;while (n--){scanf("%d%d", &x, &y);merge(x, y);}printf("Case %d: %d\n", kase++,num);}return 0;}

0 0