hdu1829A Bug's Life【并差集】

#include <iostream>
using namespace std;


//题意:判断有木有同性恋的毛毛虫
//思路：1、查看给定的图中有木有环，有环的话，就有同性恋的毛毛虫
//      2、并差集


#define NSIZ 2100
int parent[NSIZ];
int myrank[NSIZ];
int sex[NSIZ]; //sex[i] = j, 表示i与j的性格相反，性格相同的虫子在一个集合中


void make_set(int n)
{
	int i;
	memset(sex, 0, sizeof(sex));
	for(i = 1;i <= n; ++i)
	{
		parent[i] = i;
		myrank[i] = 1;
	}
}


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)
	{
		if(myrank[x] < myrank[y])
		{
			parent[x] = y;
			myrank[y] += myrank[x];
		}
		else
		{
			parent[y] = x;
			myrank[x] += myrank[y];
		}
	}
}




int main()
{  
	int n, m;
	int i, t = 1, x, y, fx, fy, icases;
	int minD,maxD;
	int isOK;
	scanf("%d", &icases);
	while(icases--)
	{
		scanf("%d %d", &n, &m);

		//init
		make_set(n);
		isOK = 0;


		for(i = 1;i <= m; ++i)
		{
			scanf("%d %d", &x, &y);
			fx = find_set(x);
			fy = find_set(y);


			if(fx == fy)
			{
				isOK = 1;
			}
			else
			{
				if(sex[x] == 0)
				{
					sex[x] = y;
				}
				else
				{
					union_set(sex[x], y);
				}




				if(sex[y] == 0)
				{
					sex[y] = x;
				}
				else
				{
					union_set(sex[y], x);
				}
			}
		}


		printf("Scenario #%d:\n", t++);
		if(!isOK)
		{
			printf("No suspicious bugs found!\n\n");
		}
		else
		{
			printf("Suspicious bugs found!\n\n");


		}
	}


	return 0;
}