Thor.md

Thor

• Problem

  http://codeforces.com/problemset/problem/704/A

• Prerequisite

  STL- Map,Queue

• Explanation

  Consider a queue e for every application and also a queue Q for the notification bar. When an event of the first type happens, increase the number of unread notifications by 1 and push pair (i, x) to Q where i is the index of this event among events of the first type, and also push number i to queue e[x]. When a second type event happens, mark all numbers in queue e[x] as visited,clear this queue and decrease the number of unread notifications by the number of elements in this queue before clearing. When a third type query happens, do the following-

  while Q is not empty and Q.front().first<=t:
    i = Q.front().first
    x= Q.front().second
    Q.pop()
         if mark[i] is false:
    	Mark[i] = true	
    e[v].pop()
    ans = ans - 1
  

• Code

  http://codeforces.com/contest/704/submission/27111975