最小公共祖先 （Tarjan） POJ1470

POJ 1470

标准的LCA，输入感觉怪怪的=.=

自己看了下Tarjan，再参考了下别人的处理方法(感觉自己好弱。。)

#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
using namespace std;

const int N = 1010;
const int M = 1000010;

int in[N], par[N], ans[N];
bool vis[N];
int n, edge, m;

struct ST
{
    int top;
    int next[M],key[M],head[N];
    void add(int x,int y)
    {
        key[top] = y;       //记录儿子
        next[top] = head[x];          
        head[x] = top++;
    }
    void clear()
    {
        top = 0;
        memset(head,-1,sizeof(head));
    }
}son,q;

int fin(int x)
{
    if(x != par[x])
        par[x] = fin(par[x]);
    return par[x];
}

void lca(int cur)
{
    par[cur] = cur;
    for(int i = son.head[cur];i != -1;i = son.next[i])
    {
        lca(son.key[i]);
        par[son.key[i]] = cur;
    }
    vis[cur] = true;
    for(int i = q.head[cur];i!= -1;i = q.next[i])
    {
        if(vis[q.key[i]])
            ans[fin(q.key[i])]++;
    }
}

void ini()
{
    memset(in,0,sizeof(in));
    memset(vis,false,sizeof(vis));
    memset(ans,0,sizeof(ans));
}

int main()
{
    int root, u, num, v;
    while(scanf("%d", &n) != EOF)
    {
        ini();
        son.clear(), q.clear();
        for(int j = 0; j < n; ++j)
        {
            scanf("%d:(%d)", &u, &num);
            for(int i = 0; i < num; ++i)
            {
                scanf("%d", &v);
                son.add(u, v);
                in[v]++;
            }
        }
    for(root = 1;in[root];root++);
    scanf("%d",&m);
    while(m--)
        {
            scanf(" (%d %d)", &u, &v);
            if(u == v)
                q.add(v, u);
            else
            {
                q.add(u, v);
                q.add(v, u);
            }
        }
        lca(root);
        for(int i = 1;i <= n;i++)
            if(ans[i])
             printf("%d:%d
", i, ans[i]);
    }
    return 0;
}