POJ 2492 A Bug's Life

题意：给出n个虫子的m种关系，这种关系表示两个虫子性别不同，问有没有产生歧义。

解法：并查集+向量偏移。跟POJ1173几乎一样。

代码：

#include<stdio.h>
#include<iostream>
#include<algorithm>
#include<string>
#include<string.h>
#include<math.h>
#include<limits.h>
#include<time.h>
#include<stdlib.h>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<vector>
#define LL long long

using namespace std;

int father[100005], delta[100005];
void init()
{
    memset(delta, 0, sizeof delta);
    for(int i = 0; i < 100005; i++)
        father[i] = i;
}
int Find(int a)
{
    if(father[a] != a)
    {
        int tmp = Find(father[a]);
        delta[a] = (delta[a] + delta[father[a]]) % 2;
        father[a] = tmp;
    }
    return father[a];
}
int main()
{
    int T;
    scanf("%d", &T);
    int cse = 1;
    while(T--)
    {
        init();
        int n, m;
        scanf("%d%d", &n, &m);
        bool ans = 0;
        while(m--)
        {
            int x, y;
            scanf("%d%d", &x, &y);
            int c = Find(x), d = Find(y);
            if(c != d)
            {
                father[c] = d;
                delta[c] = (delta[y] - delta[x] + 1) % 2;
                continue;
            }
            if(delta[x] == delta[y]) ans = 1;
        }
        printf("Scenario #%d:
", cse++);
        if(ans) puts("Suspicious bugs found!
");
        else puts("No suspicious bugs found!
");
    }
    return 0;
}