浙江大学机试 找出直系亲属 Easy *并查集

基本思想：

其实用二叉树更简单一点，但是个人认为题目有可能不太严谨，会出现多棵树情况，用二叉树一样的还是要判断节点是否在一棵树上，没啥必要；

 

关键点：

无；

 

#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<set>
#include<cmath>
using namespace std;

const int maxn = 26;
int father[maxn];


void init() {
	for (int i = 0; i < maxn; i++) {
		father[i] = i;
	}
}

int findfather(int n) {
	while (father[n] != n)
		n = father[n];
	return n;
}

void Union(int a, int b) {
	father[b] = a;
}

int find_level(int n) {
	int cnt = 0;
	while (father[n] != n) {
		cnt++;
		n = father[n];
	}
	return cnt;
}

bool is_stright(int a, int b) {
	int t1 = a;
	int t2 = b;
	while (t1 != father[t1]) {
		t1 = father[t1];
		if (b == t1)
			return true;
	}
	while (t2 != father[t2]) {
		t2 = father[t2];
		if (a == t2)
			return true;
	}
	return false;
}

void charge(int a, int b) {
	int aa = find_level(a);
	int bb = find_level(b);
	int cnt = aa - bb;
	if (cnt > 0) {
		//爷爷辈；
		if (cnt == 1) {
			cout << "parent" << endl;
		}
		else {
			string s = "grandparent";
			while (cnt != 2) {
				cnt--;
				s = "great-" + s;
			}
			cout << s << endl;
		}
	}
	else {
		cnt = abs(cnt);
		//孙子辈；
		if (cnt == 1) {
			cout << "child" << endl;
		}
		else {
			string s = "grandchild";
			while (cnt != 2) {
				cnt--;
				s = "great-" + s;
			}
			cout << s << endl;
		}
	}
}

int main() {
	int m, n;
	string s;
	while (cin >> n >> m) {
		init();
		for (int i = 0; i < n; i++) {
			cin >> s;
			for (int i = 1; i < 3; i++) {
				if (s[i] != '-')
					Union(s[0] - 'A', s[i] - 'A');
			}
		}
		for (int i = 0; i < m; i++) {
			cin >> s;
			if (!is_stright(s[0] - 'A', s[1] - 'A')) {
				cout << '-' << endl;
				continue;
			}
			charge(s[0] - 'A', s[1] - 'A');
		}
	}
}