POJ1463 Strategic game(树形DP)

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
using namespace std;
int d[1505][2],c[1505],to1[3010],next1[3010],begin1[3010],e,h;
void add(int x,int y){//链式前向星
to1[e]=y;
next1[e]=begin1[x];
begin1[x]=e++;
}
void dfs(int h){//深搜
int i,j,k;
c[h]=1;
d[h][1]=1;
d[h][0]=0;
for(i=begin1[h];i!=-1;i=next1[i]){//遍历
int t=to1[i];
if(!c[t]){
dfs(t);
d[h][0]+=d[t][1];//状态转移
d[h][1]+=min(d[t][1],d[t][0]);
}
}
}
int main(void){
int i,j,k,x,y,n,m;
while(scanf("%d",&n)!=EOF){
memset(c,0,sizeof(c));
memset(d,0,sizeof(d));
e=0;
h=-1;
memset(begin1,-1,sizeof(begin1));//清空
for(i=1;i<=n;i++){
scanf("%d:(%d)",&x,&m);
if(h==-1)h=x;
for(j=0;j<m;j++){
scanf("%d",&y);
add(x,y);
add(y,x);
}

}

dfs(h);
printf("%d\n",min(d[h][0],d[h][1]));//输出
}
return 0;
}