HDU 1011 Starship Troopers tree DP

The question is that there are n rooms to form a tree. You have m soldiers. Starting from Room 1, the soldiers start to depart from the adjacent room. Each room has a price, the price is/20 soldiers,

At the same time, there is a value, asking you how much value the M soldiers can get.

When DP [I] [J] is defined to indicate that the root node is I, the maximum possible obtained by J soldiers is used.

DP [I] [J] = max (DP [I] [J], DP [I] [J-K] + dp [son [I] [k]);

#include <cstdio>#include <cstring>#include <algorithm>#include <vector>using namespace std;vector <int> g[120];int n,m;int dp[120][120];int num[120],val[120];void dfs(int u,int fa){    int i,j,k;    int v;    for(i=num[u];i<=m;i++) dp[u][i]=val[u];    for(i=0;i<g[u].size();i++)    {        v=g[u][i];        if(v==fa) continue;        dfs(v,u);        for(j=m;j>=num[u];j--)            for(k=1;k<=j-num[u];k++)                dp[u][j]=max(dp[u][j],dp[u][j-k]+dp[v][k]);    }}int main(){    while(scanf("%d%d",&n,&m),n!=-1&&m!=-1)    {        int i,j,x,y;        for(i=1;i<=n;i++)        {            scanf("%d%d",&x,&y);            x=(x+19)/20;            num[i]=x;            val[i]=y;        }        memset(dp,0,sizeof(dp));        for(i=1;i<=n;i++) g[i].clear();        for(i=1;i<n;i++)        {            scanf("%d%d",&x,&y);            g[x].push_back(y);            g[y].push_back(x);        }        if(m==0) {printf("0\n");continue;}        dfs(1,-1);        printf("%d\n",dp[1][m]);    }    return 0;}

 

HDU 1011 Starship Troopers tree DP