题解 | #找出直系亲属#

利用并查集加各种判断，整了一个多小时
#include<iostream>
using namespace std;
#define N 30
int father[N];
int num;

//初始化并查集
void Init() {
	for (int i = 1; i <= N; i++) {
		father[i] = i;
	}
}

void Findrelation(int x,int y) {
	if (father[y] != x) {
		Findrelation(x,father[y]);
		num++;
	}
	return;
}

void Union(int x, int y) {
	if (x != y) {
		father[y] = x;
	}
}


//非路径压缩版本
int  Find(int x,int y) {
	int a = x, b = y;
	while (father[x] != x) {
		x = father[x];
		if (x == y) return 1;
	}
	while (father[b] != b) {
		b = father[b];
		if (a == b) return 2;
	}
	
	return  3;  // 1表示x为y的祖先 ，2表示y为x祖先，3表示没有关系
	
}


int main() {
	//用1到26表示A到Z
	int n, m;

	while (cin >> n >> m) {
		Init();
		for (int i = 0; i < n; i++) {
			char a, b, c;
			cin >> a >> b >> c;
			Union(a - 'A' + 1, b - 'A' + 1);
			Union(a - 'A' + 1, c - 'A' + 1);
		}
		for (int i = 0; i < m; i++) {
			char a, b;
			cin >> a >> b;
			num = 0;
			
			if (Find(a-'A'+1,b-'A'+1) == 3) {
				cout << '-' << endl;
				continue;
			}

			if (Find(a - 'A' + 1, b - 'A' + 1) == 1)
			{
				Findrelation(b - 'A' + 1, a - 'A' + 1);
				if (num == 0)
					cout << "parent" << endl;
				else if (num > 0)
				{
					while ((num--) > 1) {
						cout << "great-";
					}
					cout << "grandparent" << endl;
				}
			}
			else {
				Findrelation(a - 'A' + 1, b - 'A' + 1);
				if (num == 0)
					cout << "child" << endl;
				else if (num > 0)
				{
					while ((num--) > 1) {
						cout << "great-";
					}
					cout << "grandchild" << endl;
				}


			}
			
		}

	}

}