P3367 Parallel Search (Introductory Template Questions) (Detailed)

topic link

Topic description

As the title, now there is a union query set, you need to complete the merge and query operations.

input format

The first line contains two integers N, M, representing a total of N elements and M operations.

Next M lines, each line contains three integers Z _i , X _i , Y _i .
When Z _i = 1, merge the sets where X _i and Y _i are.
When Z _i = 2, output whether X _i and Yi _i are in the same set, yes, output Y; otherwise, output N.

output format

For each operation with Z _i = 2, there is a line of output, each line containing an uppercase letter, either Y or N.

Input and output example

Enter #1

4 7
2 1 2
1 1 2
2 1 2
1 3 4
2 1 4
1 2 3
2 1 4

output #1

N
Y
N
Y

Instructions/Tips

For 30% of the data, N ≤ 10, M ≤ 20.

For 70% of the data, N ≤ 100, M ≤ 10 ³ .

For 100% of the data, 1 ≤ N ≤ 10 ⁴ , 1 ≤ M ≤ 2 × 10 ⁵ .

AC code:

( Function details )

#include <cstdio>
const int maxn = 1e4+5;
int f[maxn], h[maxn];
int n, m, z, x, y;
void Init() {
    
    
	for(int i=1; i<=n; i++) {
    
    
		f[i] = i;
		h[i] = 0;
	}
}
int Find(int x) {
    
    
	return f[x]==x ? f[x] : f[x] = Find(f[x]);
}
void merge(int a, int b) {
    
    
	int fa = Find(a);
	int fb = Find(b);
	if(fa==fb) return; 
	
	if(h[fa] < h[fb])
		f[fa] = fb;
	} else {
    
    
		f[fb] = fa; 
		if(h[fa] == h[fb]) h[fa]++;
	}
}

int main() {
    
    
	scanf("%d %d", &n, &m);
	Init();  //记住一定要先初始化
	// 本题只有一组数据，但若有多组数据，每次都需先进行初始化！！
	while(m--) {
    
    
		scanf("%d %d %d", &z, &x, &y);
		if(z==1) {
    
       //由题：当 z为 1时
			merge(x,y);  //合并两个元素
		} else if(z==2) {
    
       //当 z为2时
			if(Find(x)==Find(y))  //如果两个元素的根相同
				printf("Y\n");    //则输出Y
			else                  //如果两个元素的根不同
				printf("N\n");    //则输出N
		}
	}
    return 0;
}