P1273 有线电视网

就是一个普通的树形dp,看错了题目的输入一直wa。

// luogu-judger-enable-o2
#include 
using namespace std;
const int maxn = 3010;
vector G[maxn];
int dp[maxn][maxn];
int vis[maxn][maxn];
int val[maxn];

struct Edge {
    int to,cost;
    Edge(int _to,int _cost):to(_to),cost(_cost){};
};
vector edges;
void addedge(int fo,int to,int cost)
{
    Edge e(to,cost),e1(fo,cost);
    edges.push_back(e);
    G[fo].push_back(edges.size()-1);
    edges.push_back(e1);
    G[to].push_back(edges.size()-1);
}
int n,m;

int DP(int u,int fa)
{
    int len = G[u].size();
    dp[u][0]=0;
    vis[u][0] = 1;
    if(len==1)
    {
        dp[u][1]=val[u];
        vis[u][1]=1;
        return 1;
    }
    int sum = 0;
    for (int i=0;i=1;j--) {
            for (int h=1;h<=j;h++) {
                if(j>=h&&vis[v][h]&&vis[u][j-h]) {
                    if(vis[u][j])
                        dp[u][j] =max(dp[u][j],dp[u][j-h]+dp[v][h]-e.cost);
                    else  {
                        dp[u][j] =dp[u][j-h]+dp[v][h]-e.cost;
                         vis[u][j] = 1;
                }

                }
            }
        }
    }
    return sum;

}

int main() {
    //freopen("in.txt","r",stdin);
    cin>>n>>m;
    memset(vis,0,sizeof(vis));
    for (int i=1;i<=n-m;i++){
        int k;
        cin>>k;
        for (int j=1;j<=k;j++) {
            int to,c;
            cin>>to>>c;
            addedge(i,to,c);
        }
    }
    for (int i=n-m+1;i<=n;i++) {
        int tep;
        cin>>tep;
        val[i] = tep;
        //cin>>val[i];
    }
    int al = DP(1,0);
    for (int i=al;i>=0;i--)
    {
        if(dp[1][i]>=0) {
            al=i;break;
        }
    }
    cout<