【模板】按秩合并的并查集、带权并查集

C++版本：

按秩合并的并查集

int init(int n) {	//初始化
	for (int i = 0; i < n; i++) {
		fa[i] = i;
		rank[i] = 0;
	}
}
int find(int x) {	//查询
	if (fa[x] == x) {
		return x;
	}
	else {
		return find(fa[x]);
	}
}
void unite(int x, int y) {	 //合并
	x = find(x);
	y = find(y);
	if (x == y)return;
	if (rank[x] < rank[y]) {
		fa[x] = y;
	}
	else {
		fa[y] = x;
		if (rank[x] == rank[y])rank[x]++;
	}
}
bool same(int x, int y) {
	return find(x) == find(y);
}

带权并查集

int ABs(int x) {
	return x >= 0 ? x : (-1)*x;
}
void INit(int n) {
	for (int i = 0; i <= n; i++)fa[i] = i, num[i] = 1;
}
int FInd(int x) {
	if (fa[x] != x) {
		int k = fa[x];
		fa[x] = FInd(fa[x]);
		dist[x] += dist[k];
		num[x] = num[fa[x]];
	}
	return fa[x];
}
void UNite(int x, int y) {
	x = FInd(x), y = FInd(y);
	if (x != y) {
		fa[x] = y;
		dist[x] = dist[y] + num[y];
		num[y] += num[x];
		num[x] = num[y];
	}
}
int QUery(int x, int y) {
	int xd = FInd(x), yd = FInd(y);
	if (xd != yd) {
		return -1;
	}
	else return ABs(dist[x] - dist[y]) - 1;
}