poj 1470 Closest Common Ancestors(LCA)

题目链接：http://poj.org/problem?id=1470

题意：LCA

方法：Tarjin 或 RMQ

裸题，不解释，就是输入有点麻烦。。。

#include<iostream>#include<cstdio>#include<cstring>#include<vector>using namespace std;#define clr(arr,v) memset(arr,v,sizeof(arr))const int M = 1005;int h[M],num[M],nex[M],pos;bool flag[M],degree[M];int cnt[M],father[M],ancestor[M];vector<int> Q[M];void init(){pos = 0;for(int i = 0;i < M;++i){Q[i].clear();cnt[i] = 0;h[i] = -1;degree[i] = false;flag[i] = false;}}void add(int u,int v){num[pos] = v;nex[pos] = h[u];h[u] = pos++;}void make_set(int u){father[u] = u;ancestor[u] = u;}int find(int u){return father[u] == u?u:father[u] = find(father[u]);}void Union(int u,int v){father[find(u)] = find(v);}void tarjin_lca(int u){make_set(u);for(int i = h[u];i != -1;i = nex[i]){tarjin_lca(num[i]);Union(u,num[i]);ancestor[find(u)] = u;}flag[u] = true;for(int i = 0;i < Q[u].size();++i){int cur = Q[u][i];if(flag[cur]) cnt[ ancestor[find(cur)] ]++;}}int main(){char ch;int n,m;while(scanf("%d",&n) != EOF){init();int u,s,v;for(int i = 1;i <= n;++i){scanf("%d",&u);while((ch = getchar()) && ch != '(');scanf("%d",&s);while((ch = getchar()) && ch != ')');for(int j = 0;j < s;++j){scanf("%d",&v);add(u,v);degree[v] = true;}}scanf("%d",&m);for(int i = 0;i < m;++i){while((ch = getchar()) && ch != '(');scanf("%d%d",&u,&v);Q[u].push_back(v);Q[v].push_back(u);while((ch = getchar()) && ch != ')');}for(int i = 1;i <= n;++i){if(!degree[i]) tarjin_lca(i);}for(int i = 1;i <= n;++i){if(cnt[i] != 0){printf("%d:%d\n",i,cnt[i]);}}}return 0;}