数据结构算法(4)--并查集

数据结构算法(4)--并查集

并查集的使用

---

Note:

#include <iostream>
using namespace std;

int father[5001];

//寻找父节点
int find(int node)
{
	if (father[node] == node)
		return node;
	return father[node] = find(father[node]);//路径压缩
}

//合并两个集合
void Union(int i, int j)
{
	int p1 = find(i);
	int p2 = find(j);
	if (p1 != p2)
	{
		if (p1 < p2)//取值较小节点为父节点
		{
			father[p2] = p1;
		}
		else
		{
			father[p1] = p2;
		}
	}
}
//判断两个节点是否在同一集合中
bool Different(int i, int j)
{
	int p1 = find(i);
	int p2 = find(j);
	if (p1 != p2)
		return true;
	else
		return false;
}
int main()
{
	
	int n, m, p;
	cin >> n >> m >> p;
	for (int i = 1; i <= n; ++i)
		father[i] = i;
	for (int i = 0; i < m; ++i)
	{
		int t1, t2;
		cin >> t1 >> t2;
		if(t1!=t2)
			Union(t1, t2);
	}
	for (int i = 0; i < p; ++i)
	{
		int t1, t2;
		cin >> t1 >> t2;
		if (Different(t1, t2))
			cout << "No" << endl;
		else
			cout << "Yes" << endl;
	}

}