pku 1909 Marbles on a tree（我都不知道这能不能算DP）

 #include <vector>#include <algorithm>#include <iostream>using namespace std;struct node{int stone;int move;int left;}nodes[10000+5];vector<int> edges[10000+5];bool root[10000+5];int n,ans;int DFS(int root){nodes[root].left=nodes[root].stone-1;nodes[root].move=0;for(int i=0;i<edges[root].size();i++){DFS(edges[root][i]);nodes[root].left+=nodes[edges[root][i]].left;nodes[root].move+=abs(nodes[edges[root][i]].left)+nodes[edges[root][i]].move;}return nodes[root].move;}int main(){while(scanf("%d",&n)&&n){int ID,num,next;memset(root,1,sizeof(root));for(int i=0;i<n;i++){scanf("%d",&ID);ID--;edges[ID].clear();scanf("%d",&nodes[ID].stone);scanf("%d",&num);for(int j=0;j<num;j++){scanf("%d",&next);root[next-1]=false;edges[ID].push_back(next-1);}}for(int i=0;i<n;i++){if(root[i]){ans=DFS(i);break;}}printf("%d/n",ans);}return 0;}