poj1470 LCA Tarjan

     比较直接的题目，入门一下。

#include<map>
#include<queue>
#include<stack>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#define INF 99999999
#define ll __int64
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
using namespace std;
const int MAXN = 1010;
struct node
{
    int to;
    int v;
    int next;
}edge[MAXN*3];
int pre[MAXN],ind,vis[MAXN],n,in[MAXN],acancestor[MAXN],ans[MAXN],pa[MAXN];
int query[MAXN][MAXN];
void add(int x,int y)
{
    edge[ind].to = y;
    edge[ind].next = pre[x];
    pre[x] = ind++;
}
int find(int x)
{
    if(x != pa[x])
        pa[x] = find(pa[x]);
    return pa[x];
}
void dfs(int rt)
{
    vis[rt] = 1;
    acancestor[rt] = rt;
    for(int i=pre[rt]; i!=-1; i=edge[i].next){
        int t = edge[i].to;
        if(!vis[t]){
            dfs(t);
            int fx = find(rt);
            int fy = find(t);
            if(fx != fy){
                pa[fy] =fx;
                acancestor[fx] = rt;
            }
        }
    }
    for(int i=1; i<=n; i++){
        if(vis[i] && query[rt][i]){
            ans[acancestor[find(i)]]+=query[rt][i];
            query[rt][i] = query[i][rt] = 0;
        }
    }
}
int main()
{
    int i,j,root;
    while(scanf("%d",&n)!=EOF)
    {
        memset(query,0,sizeof(query));
        for(i=1; i<=n; i++){
            pa[i] = i;
            in[i] = 0;
        }
        ind = 1;
        memset(pre,-1,sizeof(pre));
        for(i=1; i<=n; i++){
            int u,v,t;
            scanf("%d:(%d)",&u,&t);
            while(t--)
            {
                scanf("%d",&v);
                add(u,v);
                add(v,u);
                in[v] ++;
            }
        }
        int m;
        scanf("%d",&m);
        int x,y;
        while(m--)
        {
            char c;
            cin>>c;
            scanf("%d %d)",&x,&y);
            query[x][y]++;
            query[y][x]++;
        }
        memset(acancestor,0,sizeof(acancestor));
        memset(vis,0,sizeof(vis));
        memset(ans,0,sizeof(ans));
        for(i=1; i<=n; i++){
            if(in[i] == 0){
                root = i;
                break;
            }
        }
        dfs(root);
        for(i=1; i<=n; i++){
            if(ans[i] > 0){
                printf("%d:%d
",i,ans[i]);
            }
        }
    }
    return 0;
}