【POJ 2492】【并查集】A Bug's Life

心好痛，本来懒得写，想直接套自己写的好并查集的模板的，结果发现手贱中午被自己删了，并没有软件恢复的了，都怪自己手贱，心好痛啊啊啊啊那么久写的代码啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊。只不过今天Bestcoder打的不错，终于上分了。乐极生悲啊啊啊啊。其实类似食物链，比食物链简单，属于并查集的扩展，上代码。

#include"iostream"
using namespace std;
const int Max = 2005;
int n, m;
int parent[Max], opp[Max];
void make_set()
{
    for(int x = 1; x <= n; x ++)
    {
        parent[x] = x;
        opp[x] = 0;
    }
}
int find_set(int x)
{
    if(x != parent[x])
        parent[x] = find_set(parent[x]);
    return parent[x];
}



void union_set(int x, int y)
{
    x = find_set(x);
    y = find_set(y);
    if(x == y)
        return;
    parent[y] = x;
}



int main()
{
    int t, i, x, y;
    scanf("%d", &t);
    for(i = 1; i <= t; i ++)
    {
        scanf("%d %d", &n, &m);
        make_set();
        bool flag = false;
        while(m--)
        {
            scanf("%d %d", &x, &y);
            if(flag) 
                continue;
            if(find_set(x) == find_set(y))
            {  // 若x，y同在一个集合，则证明有同性的可疑。
                flag = true;
            }
            if(opp[x] == 0 && opp[y] == 0)
            {
                opp[x] = y;//表明y是x的异性
                opp[y] = x;
            }
            else if(opp[x] == 0)
            {
                opp[x] = y;
                union_set(x, opp[y]);
            }
            else if(opp[y] == 0)
            {
                opp[y] = x;
                union_set(y, opp[x]);
            }
            else
            {
                union_set(x, opp[y]);
                union_set(y, opp[x]);
            }
        }
        printf("Scenario #%d:\n", i);
        if(flag) 
            printf("Suspicious bugs found!\n\n");
        else 
            printf("No suspicious bugs found!\n\n");
    }
    return 0;
}