Create 1579. Remove Max Number of Edges to Keep Graph Fully Traversable1 (#517)

Author: Chayandas07

1579. Remove Max Number of Edges to Keep Graph Fully Traversable1

@@ -0,0 +1,71 @@
+#include <bits/stdc++.h>
+using namespace std;
+class DisjointSetUnion { 
+    vector<int> parent;
+    vector<int> rank; 
+ 
+public:
+    DisjointSetUnion(int n) {
+        parent.resize(n);
+        rank.resize(n, 0); 
+        for (int i = 0; i < n; ++i) {
+            parent[i] = i;
+        }
+    }
+ 
+    int find(int u) {
+        if (parent[u] != u) {
+            parent[u] = find(parent[u]); // Path compression
+        }
+        return parent[u];
+    }
+ 
+    void unionByRank(int u, int v) {
+        int rootU = find(u);
+        int rootV = find(v);
+        if (rootU != rootV) {
+            if (rank[rootU] > rank[rootV]) {
+                parent[rootV] = rootU;
+            } else if (rank[rootU] < rank[rootV]) {
+                parent[rootU] = rootV;
+            } else {
+                parent[rootV] = rootU;
+                rank[rootU]++;
+            }
+        }
+    }
+};
+ 
+class Solution {
+public:
+    int maxNumEdgesToRemove(int n, vector<vector<int>>& e) {
+    DisjointSetUnion a(n+1);
+    DisjointSetUnion b(n+1);   
+    int ans=0;
+    for(auto it:e) { 
+        if(it[0]==3){ 
+            if(a.find(it[1])==a.find(it[2])){ans++; continue; }
+            a.unionByRank(it[1],it[2]);
+            b.unionByRank(it[1],it[2]);
+        } 
+    }
+    for(auto it:e) {
+        if(it[0]!=3){  
+            if(it[0]==1){
+            if(a.find(it[1])==a.find(it[2])){ans++; continue; }
+            a.unionByRank(it[1],it[2]);
+            } else {
+            if(b.find(it[1])==b.find(it[2])){ans++; continue; }
+            b.unionByRank(it[1],it[2]);
+            }
+        } 
+    }
+    int k=a.find(1);
+    for(int i=1;i<=n;i++){
+        if(k!=a.find(i) or k!=b.find(i)){
+            return -1;
+        } 
+    }
+    return ans; 
+    }
+};