disjoint set

Author: jeffin143

Data Structures/disjointset/findunion.cpp

@@ -0,0 +1,70 @@
+
+/*
+Disjoint set example of find and union 
+
+Question Url : https://www.hackerrank.com/challenges/merging-communities/problem
+
+*/
+
+#include <bits/stdc++.h>
+
+using namespace std;
+
+long find(int x,vector<int>&a)
+{
+    while(1)
+    {
+        if(a[x]<0)
+        {
+            return x;
+        }
+        else
+        {
+            x=a[x];
+        }
+    }
+}
+int main()
+{
+  int n;
+    cin>>n;
+    vector<int>arr(n+1,-1);
+    int m;
+    cin>>m;
+    int i,j,x;
+    char qt;
+    long p1,p2;
+    while(m--)
+    {
+        cin>>qt;
+        if(qt=='M')
+        {
+    
+        cin>>i>>j;
+         p1=find(i,arr);
+        p2=find(j,arr);
+        if(p1!=p2)
+        {
+            arr[p1]=arr[p1]+arr[p2];
+            arr[p2]=p1; //making p1 as parrent of that node;
+            arr[j]=p1; //collapsing the tree what i have learned to minimize the time to find the parent;    
+            
+        }
+        
+        }
+        else
+        {
+            cin>>x;
+           
+            cout<<abs(arr[find(x,arr)])<<endl;   // finding how many of them are in a group basically union set 
+        }
+    }
+  
+    
+      
+    
+    return 0;
+}
+
+
+