HDU 5452 Minimum Cut

#include <iostream>
#include <cmath>
#include <algorithm>
#include <string>
#include <deque>
#include <cstring>
#include <cstdio>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cstdlib>
using namespace std;
typedef long long LL;
const LL INF = 0xffffff;
const int maxn = 201315;
const LL MOD = 1e9+7;
vector<vector<int> >G;
int Father[maxn], Deep[maxn], ans[maxn];
int n, m;
void Init()
{
    G.clear();
    G.resize(n+2);
    memset(Deep, 0, sizeof(Deep));
    memset(ans, 0, sizeof(ans));
    memset(Father, 0, sizeof(Father));
}

void DFS(int fa,int cur,int deep)
{
    Father[cur] = fa;
    Deep[cur] = deep;
    int len = G[cur].size();
    for(int i=0; i<len; i++)
    {
        int v = G[cur][i];
        if(v != fa)
        {
            DFS(cur, v, deep+1);
        }
    }
}

void LCA(int a,int b)
{
    if(a == b)
    {
       // ans[a] -= 2;
        return ;
    }

    if(Deep[a] > Deep[b])
    {
        ans[a] ++;
        LCA(Father[a],  b);
    }

    else
    {
        ans[b] ++;
        LCA(a, Father[b]);
    }

}

int main()
{
    int T, cas = 1, a, b;
    scanf("%d", &T);

    while(T--)
    {
        scanf("%d %d",&n, &m);
        Init();

        for(int i=1; i<=n-1; i++)
        {
            scanf("%d %d", &a, &b);
            G[a].push_back(b);
            G[b].push_back(a);
        }
        DFS(0, 1, 0);
        for(int i=n; i<=m; i++)
        {
            scanf("%d %d",&a, &b);
            LCA(a, b);
        }

        int res = INF;
        for(int i=2; i<=n; i++)
            res = min(res, ans[i]);

        printf("Case #%d: %d\n", cas++, res+1);
    }
    return 0;
}