Create dsu.cpp

DSU/dsu.cpp

@@ -0,0 +1,49 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class DSU {
+public:
+  int components{};
+  vector<int> par, sz, rank; //rank is level/height of the sub-tree
+                             //sz is the number of node in sub-tree
+  DSU(int n) {
+    rank.resize(n+1, 0);
+    par.resize(n+1);
+    sz.resize(n+1, 1);
+    iota(par.begin(), par.end(), 0);
+    this -> components = n;
+  }
+
+  int find(int u) {
+    if(par[u] == u) return u;
+    return par[u] = find(par[u]);
+  }
+
+  void unionRank(int u, int v) {
+    u = find(u); v = find(v);
+    if(u == v) return;
+    components--;
+    if(rank[u] < rank[v]) par[u] = v;
+    else if(rank[v] < rank[u]) par[v] = u;
+    else {
+      par[v] = u;
+      rank[u]++;
+    }
+  }
+
+  void unionSize(int u, int v) {
+    u = find(u); v = find(v);
+    if(u == v) return;
+    components--;
+    if(sz[u] > sz[v]) swap(u, v);
+    sz[v] += sz[u];
+    par[u] = v;
+  }
+};
+
+int32_t main () {
+  ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
+  int n; cin >> n;
+  DSU dsu(n);
+}
+