Create MinOperationToConnectGraph.cpp

Graphs/MinOperationToConnectGraph.cpp

@@ -0,0 +1,68 @@
+class DisjointSet {
+    public:
+        vector<int> rank, parent;
+
+        DisjointSet(int n) {
+            rank.resize(n+1, 0);
+            parent.resize(n+1);
+
+            for(int i=0; i<=n; i++) {
+                parent[i] = i;
+            }
+        }
+
+        int findUParent(int node) {
+            if(parent[node] == node)
+                return node;
+
+            return parent[node] = findUParent(parent[node]);
+        }
+
+        void unionByRank(int u, int v) {
+            int ul_parent_u = findUParent(u);
+            int ul_parent_v = findUParent(v);
+
+            if(ul_parent_u == ul_parent_v)
+                return;
+
+            if(rank[ul_parent_u] < rank[ul_parent_v]) {
+                parent[ul_parent_u] = ul_parent_v;
+            }
+            else if(rank[ul_parent_v] < rank[ul_parent_u]) {
+                parent[ul_parent_v] = ul_parent_u;
+            }
+            else {
+                parent[ul_parent_v] = ul_parent_u;
+                rank[ul_parent_u]++;
+            }
+        }
+};
+class Solution {
+public:
+    int makeConnected(int n, vector<vector<int>>& edge) {
+         DisjointSet ds(n);
+        int cntExtra=0;
+        for(auto it:edge){
+            int u=it[0];
+            int v=it[1];
+            if(ds.findUParent(u)==ds.findUParent(v)){
+                cntExtra++;
+            }
+            else{
+                ds.unionByRank(u,v);
+            }
+        }
+        int cntC=0;
+        for(int i=0;i<n;i++){
+            if(ds.parent[i]==i){
+                cntC++;
+            }
+
+        }
+        int ans=cntC-1;
+        if(cntExtra>=ans){
+            return ans;
+        }
+        return -1;
+    }
+};