csu1326

背包的分组问题，详见背包九讲

用并查集分组、。、

#include<cstdio>#include<iostream>#include<cstring>#include<string>#include<vector>#include<algorithm>#include<time.h>#include<stdlib.h>#include<cmath>using namespace std;#define N 1005int F[N], vis[N];int W[N], P[N];int dp[N];vector<int>s[N];int find(int x){    if(x != F[x])        F[x] = find(F[x]);    return F[x];}void Union(int x, int y){    int a = find(x);    int b = find(y);    if(a != b)        F[b] = a;}int main(){    int n,Wmax,k;    while(scanf("%d%d%d",&n,&Wmax,&k)!=EOF)    {        memset(vis, 0, sizeof(vis));            memset(dp, 0, sizeof(dp));        for(int i=0;i<=n;i++)         {            F[i]=i;            s[i].clear();        }        for(int i=1;i<=n;i++)            scanf("%d%d",&P[i],&W[i]);        for(int i=0;i<k;i++)        {            int a,b;            scanf("%d%d",&a,&b);            Union(a,b);        }        for(int i=1;i<=n;i++)        {            int a=find(i);            s[a].push_back(i);        }        for(int i=1;i<=n;i++)        {            if(!s[i].size()) continue;            for(int v=Wmax;v>=0;v--)            {                for(int k=0;k<s[i].size();k++)                {                    int t=s[i][k];                    if(v>=W[t])                        dp[v]=max(dp[v],dp[v-W[t]]+P[t]);                }            }        }        printf("%d\n",dp[Wmax]);    }    return 0;}