Unread Messages
Time limit1sMemory limit512 MB
Given m messages sent by members of an n-person group, report after each message the total number of unread messages across all members.
- Level
Medium4 of 10
- Topics
- Implementation, Math, Simulation, Hash map
- Solved
- No attempts yet
Problem
There is a group of people in an internet email message group. Messages are sent to all members of the group, and no two messages are sent at the same time.
Immediately before a person sends a message, they read all their unread messages up to that point. Each sender also reads their own message the moment it is sent. Therefore, a person's unread messages are exactly the set of messages sent after that person's last message.
Each time a message is sent, compute the total number of unread messages over all group members.
Input
The first line of input contains two integers () and (), where is the number of people in the group, and is the number of messages sent. The group members are identified by number, through .
Each of the next lines contains a single integer (), which is the sender of that message. These lines are in chronological order.
Output
Output lines, each with a single integer, indicating the total number of unread messages over all group members, immediately after each message is sent.