ACM —— 1012 Joseph

解题代码：

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner stdin = new Scanner(System.in);int k;int[] joseph = new int[14];while ((k = stdin.nextInt()) != 0) {if (joseph[k] > 0) { // 每个环值是唯一的，如果计算过，直接输出System.out.println(joseph[k]);continue;}int n = 2*k;int m;Lable:for(int r = 0; ;r++) {for (int h = k+1; h <= n; h++) {m = n * r + h; // 只计算余数在（k, 2k] 区间的m值if (Joseph(k,m,n)) {break Lable;}}}joseph[k] = m;System.out.println(m);}}private static boolean Joseph(int k, int m, int n) {int a = 1;for (int i = 1; i <= k; i++) {a = (a + m - 1)%(n - i + 1); // 约瑟夫环公式if (a == 0) {a = n - i + 1;} if ((a<=k)&&(a>=0)) {return false;}}return true;}}