Card 2
InterviewTime limit2sMemory limit128 MB
Simulate the Josephus-style card elimination process to find which card number remains last for a given N.
- Level
Easy3 of 10
- Topics
- Queue, Simulation, Math
- Solved
- No attempts yet
Problem
There are N cards in a stack. The cards are numbered from 1 through N from top to bottom, so card 1 is initially on top and card N is initially on the bottom.
Repeat the following two operations until only one card remains.
- Discard the top card.
- If any cards remain, move the new top card to the bottom of the stack.
When N = 4, the initial order is 1, 2, 3, 4. After discarding 1 and moving 2 to the bottom, the order becomes 3, 4, 2. Then discard 3 and move 4 to the bottom, leaving 2, 4. Finally, discard 2, and only card 4 remains.
Given N, find the number of the last remaining card.
Input
The first line contains an integer N. (1 ≤ N ≤ 500,000)
Output
Print the number of the last remaining card on the first line.