카드 2 (원형큐/선형큐/데크)

#include <stdio.h>

int card[500000];

int main (){
	int num;

	scanf_s("%d", &num);

	for (int i = 0; i < num; i++) {
		card[i] = i + 1;
	}

	int result = num;
	int front = 0;
	int back = num-1;

	while (1)
	{
		front = (front + 1) % num;
		if (front == back) {
			break;
		}
		back = (back + 1) % num;
		card[back] = card[front];
		front = (front + 1) % num;
		if (front == back) {
			break;
		}
	}
	printf("%d", card[front]);
	return 0;
}