Poj1470 Closest Common Ancestors LCA

　　LCA裸题。。

#include<iostream>

#include<cstdio>

#include<cstring>

#include<map>

#include<vector>

using namespace std;

const int maxn = 1111;

int head[maxn];

int len;

struct Node

{

    int to; int next;

}e[maxn * 2];

int father[maxn];

int color[maxn];

int vis[maxn];

int gg[maxn];

vector <int> q[maxn];

void add(int from, int to)

{

    e[len].to = to;

    e[len].next = head[from];

    head[from] = len++;

}



int getfather(int x)

{

    if (father[x] != x) father[x] = getfather(father[x]);

    return father[x];

}



void un(int a, int b)

{

    int fa = getfather(a); int fb = getfather(b);

    father[fb] = fa;

}





void dfs(int x)

{

    for (int i = head[x]; ~i; i = e[i].next){

        int cc = e[i].to;

        dfs(cc);

        un(x, cc);

    }

    color[x] = 1;

    for (int i = 0; i <q[x].size(); i++){

        int t = q[x][i];

        if (color[t]){

            int t1 = getfather(q[x][i]);

            vis[t1]++;

        }

    }

}



void init(int n)

{

    len = 0;

    memset(head, -1, sizeof(head));

    for (int i = 1; i <= n; i++)

        father[i] = i;

    memset(head, -1, sizeof(head));

    for (int i = 1; i <= n; i++)

        q[i].clear();

    memset(color, 0, sizeof(color));

    for (int i = 1; i <= n; i++)

        vis[i] = 0;

    for (int i = 1; i <= n; i++)

        gg[i] = 0;

}





int main()

{

    int n;

    while (cin >> n){

        init(n);

        int m, a, b, c;

        for (int i = 0; i<n; i++){

            scanf("%d", &a);

            scanf(":(%d)", &b);

            for (int j = 0; j<b; j++){

                scanf("%d", &c);

                add(a, c);

                gg[c] = 1;

            }

        }

        scanf("%d", &m);

        while (m--){

            scanf(" (%d %d)", &a, &b);

            //  printf("%d %djiji\n",a,b);

            q[a].push_back(b);

            q[b].push_back(a);

        }

        int root;

        for (int i = 1; i <= n; i++) if (!gg[i]){

            root = i; break;

        }

        dfs(root);

        for (int i = 1; i <= n; i++){

            if (vis[i]){

                printf("%d:%d\n", i, vis[i]);

            }

        }

    }

    return 0;

}