Create DisjointSetUnion.cpp

DisjointSetUnion.cpp

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+// Example implementation of Disjoint Set Union
+
+//////////////////////////////////////////////////////////////////
+/////                                                           //
+////  Credits: Rahul Verma (CC @vrintle, CF @BlindingKnight)   ///
+///  Institution: Delhi Technological University (aka. DCE)   ////
+//                                                           /////
+//////////////////////////////////////////////////////////////////
+
+#include <chrono>
+#include <bits/stdc++.h>
+using namespace std;
+using namespace chrono;
+
+class DSU {
+public:
+	vector<int> head;
+	vector<int> size;
+	DSU(int n) {
+		head.assign(n + 1, 0);
+		size.assign(n + 1, 1);
+		for(int i = 1; i <= n; i++) {
+			head[i] = i;
+		}
+	}
+	int get(int x) {
+		if(x != head[x]) {
+			head[x] = get(head[x]);
+		}
+		return head[x];	
+	}
+	void U(int a, int b) {
+		// we'll assume a as "head"
+		a = get(a);
+		b = get(b);
+		if(a == b) return ;
+		if(size[a] < size[b]) swap(a, b);
+		head[b] = a;
+		size[a] += size[b];
+	}
+};
+
+void solve() {
+	int n, m;
+	cin >> n >> m;
+	DSU set(n);
+	while(m--) {
+		string s;
+		int a, b;
+		cin >> s >> a >> b;
+		if(s == "union") {
+			set.U(a, b);
+		} else {
+			cout << (set.get(a) == set.get(b) ? "YES" : "NO") << '\n';
+		}
+	}
+}
+
+int32_t main() {
+	auto start = high_resolution_clock::now();
+	ios_base::sync_with_stdio(false);
+	cin.tie(NULL);
+	int t = 1;
+	cin >> t;
+	while(t--) {
+		solve();
+	}
+	auto stop = high_resolution_clock::now();
+	auto duration = duration_cast<microseconds>(stop - start);
+	cerr << duration.count() << " µs!" << '\n';
+	return 0;
+}