Update Persistent Segment Tree.cpp

Author: Ashishgup1

Persistent Segment Tree.cpp

@@ -56,3 +56,6 @@ void persistentSegTree()
 
 //Problem 2 (Kth element in sorted range [i, j]): https://www.spoj.com/problems/MKTHNUM/
 //Solution 2: http://p.ip.fi/B00r
+
+//Problem 3 (Take atmost K values of a particular value in a range): https://codeforces.com/contest/813/problem/E
+//Solution 3: https://codeforces.com/contest/813/submission/50422337