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

Added Problem Link at start

Author: saiteja-2731

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;
+ }
+};