Create 684. Redundant Connection (#700)

684. Redundant Connection

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+class DisjointSet {
+private:
+    vector<int> parent;
+public:
+    DisjointSet(int n) {
+        parent.resize(n+1);
+        for (int i = 1; i < n + 1; ++i) {
+            parent[i] = i; //initially all nodes are set as independent 
+        }
+    }
+    int find(int u) {
+        if (parent[u] == u) return u;
+        return parent[u] = find(parent[u]);
+    }
+    bool Union(int u, int v) {
+        int parU = find(u);
+        int parV = find(v);
+        if (parU != parV) { // not part of the set yet
+            parent[parV] = parU;
+            return true;
+        } else return false; // already part of the set
+
+    }
+};
+class Solution {
+public:
+    vector<int> findRedundantConnection(vector<vector<int>>& edges) {
+        int n = edges.size(); //here graphs with n nodes have n edges 
+        DisjointSet ds(n);
+        for (const auto &edge : edges) {
+            int u = edge[1], v = edge[0];
+            if (!ds.Union(u, v)) return edge;
+        }
+        return {};
+    }
+};