Added Redundant connections problem from Leetcode-684 (codedecks-in#192)

saiteja-2731 · web-flow · commit d012f3a74fbf · 2021-10-01T15:42:37.000+05:30
Added Problem Link at start
diff --git a/C++/RedundantConnection.cpp b/C++/RedundantConnection.cpp
@@ -0,0 +1,46 @@
+/*
+ProblemLink : https://leetcode.com/problems/redundant-connection/
+
+In this problem, a tree is an undirected graph that is connected and has no cycles.
+
+You are given a graph that started as a tree with n nodes labeled from 1 to n, with one additional edge added.
+The added edge has two different vertices chosen from 1 to n, and was not an edge that already existed. 
+The graph is represented as an array edges of length n where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the graph.
+
+Return an edge that can be removed so that the resulting graph is a tree of n nodes. 
+If there are multiple answers, return the answer that occurs last in the input.
+*/
+
+class Solution {
+public:
+    int find(int v,vector<int>& parent){
+        if(parent[v]==-1){
+            return v;
+        }
+        return find(parent[v],parent);
+    }
+    void Union(int x,int y,vector<int>& parent){
+        parent[x]=y;
+    }
+    
+    vector<int> findRedundantConnection(vector<vector<int>>& edges) {
+        int V = edges.size();
+        vector<int> parent(V+1,-1);
+        int v1,v2;
+        for(auto x:edges){
+            int fromP = find(x[0],parent);
+            int toP = find(x[1],parent);
+            if(fromP==toP){
+                v1=x[0];
+                v2=x[1];
+            }
+            else{
+                Union(fromP,toP,parent);
+            }
+        }
+        vector<int> ans;
+        ans.push_back(v1);
+        ans.push_back(v2);
+        return ans;
+    }
+};
