标签:style blog http color os io for art
题意:给一个无向图。每次查询破坏一条边,每次输出查询后连通图的个数。
思路:并查集。逆向思维,删边变成加边。
#include<cstdio> #include<cstring> #include<algorithm> #include<vector> #include<iostream> #define inf -100000000 #define LL long long #define maxn 100005 using namespace std; struct Edge { int x,y; }; int parent[maxn]; int findset(int p) { return (parent[p]==p)?p:(parent[p]=findset(parent[p])); } Edge edge[maxn]; int query[maxn]; bool build[maxn]; int ans[maxn]; int main() { int n,m; while(scanf("%d%d",&n,&m)!=EOF) { memset(build,0,sizeof(build)); for(int i=1; i<=m; ++i) scanf("%d%d",&edge[i].x,&edge[i].y); int q; scanf("%d",&q); for(int i=1; i<=q; ++i) { scanf("%d",&query[i]); build[query[i]]=true; } for(int i=1; i<=n; ++i) parent[i]=i; int cnt=0; for(int i=1; i<=m; ++i) if(!build[i]) { int fa=findset(edge[i].x),fb=findset(edge[i].y); if(fa!=fb) parent[fa]=fb; } for(int i=1; i<=n; ++i) if(findset(i)==i) cnt++; for(int i=q; i>=1; --i) { ans[i]=cnt; int fa=findset(edge[query[i]].x),fb=findset(edge[query[i]].y); if(fa!=fb) { parent[fa]=fb; cnt--; } } for(int i=1; i<=q; ++i) if(i==1) printf("%d",ans[i]); else printf(" %d",ans[i]); printf("\n"); } return 0; }
URAL 1671 Anansi's Cobweb (并查集),布布扣,bubuko.com
URAL 1671 Anansi's Cobweb (并查集)
标签:style blog http color os io for art
原文地址:http://www.cnblogs.com/kkkwjx/p/3884624.html