05-树8 File Transfer【并查集】

来源：互联网发布：数据通信与网络第四版编辑：程序博客网时间：2024/06/09 22:12

题目：File Transfer

题意：输入形式有3种：“I a b"代表：a,b可连通；“C a b”代表：查询a,b是否连通；“S”代表结束。输出查询是否连通即可。

思路：基本的并查集操作！

代码：

#include <cstdio>#include <cstring>const int maxn = 10005;int f[maxn];void init(int n){for(int i=0;i<=n;i++) f[i] = i;}inline int find(int v){if(f[v] != v) f[v] = find(f[v]);return f[v];}inline void merge(int u,int v){int tu = find(u);int tv = find(v);if(tu != tv) f[tv] = tu;}int main(){int n,u,v;char s[5];while(scanf("%d",&n)!=EOF){init(n);while(scanf("%s",s) && s[0] != 'S'){scanf("%d%d",&u,&v);if(s[0] == 'I') merge(u,v);else{if(find(u) == find(v)) printf("yes\n");else printf("no\n");}}int cnt = 0;for(int i=1;i<=n;i++){if(f[i] == i) cnt++;}if(cnt > 1) printf("There are %d components.\n",cnt);else printf("The network is connected.\n");}}

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