【POJ 1463】Strategic game

#include<bits/stdc++.h>
using namespace std;
#define File ""
#define ll long long
inline void file(){
    freopen(File".in","r",stdin);
    freopen(File".out","w",stdout);
}
inline int read(){
    int x = 0,f = 1; char ch = getchar();
    while(ch < '0'||ch > '9'){if(ch == '-')f = -1; ch = getchar();}
    while(ch >= '0' && ch <= '9'){x = (x<<1) + (x<<3) + ch-'0'; ch = getchar();}
    return x * f;
}
const int mxn = 1500+10;
struct edge{
    int y,nxt;
}e[mxn<<1];

int to[mxn],len;
inline void add(int xx,int yy){
    e[++len].nxt = to[xx];
    to[xx] = len;
    e[len].y = yy;
}

bool v[mxn];
int f[mxn][2];
inline void dp(int x){
    v[x] = 1;
    f[x][0] = 0,f[x][1] = 1;
    for(int i = to[x]; i;i = e[i].nxt){
        int y = e[i].y;
        if(v[y]) continue;
        dp(y);
        f[x][0] += f[y][1];
        f[x][1] += min(f[y][0],f[y][1]);
    }
}
int n,m,k;
int main(){
//    file();
    while(~scanf("%d
",&n)){
        memset(to,0,sizeof to);
        len = 1;
        for(int i = 1;i <= n; ++i){
            scanf("%d:(%d)",&m,&k);
            while(k--){
                int x = read();
                add(m,x),add(x,m);
            }
        }
        int ans(0);
        memset(v,0,sizeof v);
        for(int i = 0;i < n; ++i){
            if(v[i]) continue;
            dp(i);
            ans += min(f[i][0],f[i][1]);
        }
        printf("%d
",ans);
    }
    return 0;
}
/*
4
0:(1) 1
1:(2) 2 3
2:(0)
3:(0)
5
3:(3) 1 4 2
1:(1) 0
2:(0)
0:(0)
4:(0)
*/