java編程思想_009吸血鬼數字

package com.wzs;// 吸血鬼數字是指位元為偶數的數字，可以由一對數值相乘獲得，以兩個零結尾的數值是不允許的// 例如:1260=21*60 1827=21*87 2187=27*81public class Test {public static void main(String[] args) {for (int i = 1000; i < 9999; i++) {isBloodsucker(i, com(a(i), b(i)), com(c(i), d(i)));isBloodsucker(i, com(a(i), b(i)), com(d(i), c(i)));isBloodsucker(i, com(a(i), c(i)), com(b(i), d(i)));isBloodsucker(i, com(a(i), c(i)), com(d(i), b(i)));isBloodsucker(i, com(a(i), d(i)), com(b(i), c(i)));isBloodsucker(i, com(a(i), d(i)), com(c(i), b(i)));isBloodsucker(i, com(b(i), a(i)), com(c(i), d(i)));isBloodsucker(i, com(b(i), a(i)), com(d(i), c(i)));isBloodsucker(i, com(b(i), c(i)), com(d(i), a(i)));isBloodsucker(i, com(b(i), d(i)), com(c(i), a(i)));isBloodsucker(i, com(c(i), a(i)), com(d(i), b(i)));isBloodsucker(i, com(c(i), b(i)), com(d(i), a(i)));}}// 判斷是否吸血鬼數字static void isBloodsucker(int i, int m, int n) {if (i == m * n) {System.out.println(i + " = " + m + " * " + n);}}// 組合成兩位元static int com(int i, int j) {return (i * 10) + j;}// 千位static int a(int i) {return i / 1000;}// 百位static int b(int i) {return (i % 1000) / 100;}// 十位static int c(int i) {return ((i % 1000) % 100) / 10;}// 個位static int d(int i) {return ((i % 1000) % 100) % 10;}}

輸出結果:

1260 = 21 * 601395 = 15 * 931435 = 41 * 351530 = 51 * 301827 = 87 * 212187 = 27 * 816880 = 86 * 806880 = 80 * 86