Codeforces 741B Arpa's weak amphitheater and Mehrdad's valuable Hoses
Posted forever97‘s blog
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了Codeforces 741B Arpa's weak amphitheater and Mehrdad's valuable Hoses相关的知识,希望对你有一定的参考价值。
【题目链接】 http://codeforces.com/problemset/problem/741/B
【题目大意】
给出一张图,所有连通块构成分组,每个点有价值和代价,
要么选择整个连通块,要么只能在连通块中选择一个,或者不选,为最大价值
【题解】
首先我们用并查集求出连通块,然后对连通块进行分组背包即可。
【代码】
#include <cstdio> #include <vector> #include <algorithm> #include <cstring> #define rep(i,n) for(int i=1;i<=n;i++) using namespace std; const int N=1010; int dp[N],f[N],n,m,x,y,size,w[N],b[N]; vector<int> v[N]; int sf(int x){return f[x]==x?x:f[x]=sf(f[x]);} int main(){ while(~scanf("%d%d%d",&n,&m,&size)){ rep(i,n)f[i]=i,v[i].clear(); rep(i,n)scanf("%d\n",&w[i]); rep(i,n)scanf("%d\n",&b[i]); rep(i,m){scanf("%d%d",&x,&y);f[sf(x)]=sf(y);} rep(i,n)v[sf(i)].push_back(i); memset(dp,0,sizeof(dp)); rep(i,n)if(sf(i)==i){ for(int j=size;j>=0;j--){ int W=0,B=0; for(int k=0;k<v[i].size();k++){ W+=w[v[i][k]]; B+=b[v[i][k]]; if(j>=w[v[i][k]])dp[j]=max(dp[j],dp[j-w[v[i][k]]]+b[v[i][k]]); }if(j>=W)dp[j]=max(dp[j],dp[j-W]+B); } }printf("%d\n",dp[size]); }return 0; }
以上是关于Codeforces 741B Arpa's weak amphitheater and Mehrdad's valuable Hoses的主要内容,如果未能解决你的问题,请参考以下文章
并查集+背包 CF741B Arpa's weak amphitheater and Mehrdad's valuable Hoses
Arpa's weak amphitheater and Mehrdad's valuable Hoses CodeForces - 742D
codeforces 742D Arpa's weak amphitheater and Mehrdad's valuable Hoses ——(01背包变形)
Codeforces 741B-Arpa's weak amphitheater and Mehrdad's valuable Hoses
http://codeforces.com/contest/741/problem/B B. Arpa's weak amphitheater and Mehrdad's valuab
D. Arpa's weak amphitheater and Mehrdad's valuable Hoses 分组背包模板题