Create AccountMerge.cpp

Graphs/AccountMerge.cpp

@@ -0,0 +1,81 @@
+// User function Template for C++
+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:
+    vector<vector<string>> accountsMerge(vector<vector<string>> &accounts) {
+        // code here
+        int n=accounts.size();
+        unordered_map<string,int>m;
+        DisjointSet ds(n);
+        for(int i=0;i<n;i++){
+            for(int j=1;j<accounts[i].size();j++){
+                string mail=accounts[i][j];
+            if(m.find(mail)==m.end()){
+                m[mail]=i;
+            }
+            else{
+                ds.unionByRank(i,m[mail]);
+            }
+            }
+        }
+        vector<string> mergeMail[n];
+        for(auto it:m){
+            string mail=it.first;
+            int node=ds.findUParent(it.second);
+            mergeMail[node].push_back(mail);
+        }
+        vector<vector<string>>ans;
+        for(int i=0;i<n;i++){
+            if(mergeMail[i].size()==0){
+                continue;
+            }
+            sort(mergeMail[i].begin(),mergeMail[i].end());
+            vector<string>temp;
+            temp.push_back(accounts[i][0]);
+            for(auto it:mergeMail[i]){
+                temp.push_back(it);
+            }
+            ans.push_back(temp);
+        }
+        return ans;
+    }
+};