洛谷 P1145 約瑟夫

傳送門

#include <iostream>
using namespace std;
int main()
{
	int k, killed;
	cin >> k;
	int m = k;
	while (1)
	{
		m++;
		killed = 0;
		for (int i=0; i < k; i++)
		{
			killed = (killed + m - 1) % (2 * k - i);   //關鍵代碼
			if (killed < k)
				break;
			if (i == k - 1)
			{
				cout << m;
				return 0;
			}
		}
	}
	return 0;
}