［fun code - 模拟］孤独的“7”

今天看到朋友圈里有人发了一张孤独的7的题目，第一反应就是模拟后计算出结果，而女朋友则更爱推理，手算。😄

java code:

import java.io.ObjectInputStream.GetField;

/**
 * Project Name:fun
 * File Name:Main.java
 * Package Name:
 * Date:Aug 30, 20152:58:38 PM
 * Copyright (c) 2015, max_xbw@163.com All Rights Reserved.
 *
 */
/**
 * ClassName:Main <br/>
 * Function: TODO ADD FUNCTION. <br/>
 * Reason: TODO ADD REASON. <br/>
 * Date: Aug 30, 2015 2:58:38 PM <br/>
 * 
 * @author xubowen
 * @version
 * @since JDK 1.7
 * @see
 */
public class Main {

    static long getnum(long num, int st, int et) {
        st--;
        String numstr = String.valueOf(num);
        String numstrt = numstr.substring(st, et);
        return Long.valueOf(numstrt);
    }

    public static void main(String[] args) {
        for (int xa = 1; xa <= 9; xa++) {
            for (int xb = 0; xb <= 9; xb++) {
                for (int xc = 0; xc <= 9; xc++) {
                    long x = xa * 100 + xb * 10 + xc;
                    for (int ya = 1; ya <= 9; ya++) {
                        int yb = 7;
                        for (int yc = 0; yc <= 9; yc++) {
                            int yd = 0;
                            for (int ye = 0; ye <= 9; ye++) {
                                long y = ya * 10000 + yb * 1000 + yc * 100 + yd
                                        * 10 + ye;
                                long z = x * y;
                                // 第一行
                                // ya*x<1000
                                long tmp1a = ya * x;
                                if (tmp1a < 1000) {
                                    continue;
                                }
                                // 取z的前四位数
                                long tmp1b = getnum(z, 1, 4);
                                if (tmp1b - tmp1a >= 100) {
                                    continue;
                                }
                                long tmp1 = tmp1b - tmp1a;
                                // 第二行
                                // 3位数
                                long tmp2a = yb * x;
                                if (tmp2a >= 1000) {
                                    continue;
                                }
                                long tmp2b = tmp1 * 10 + getnum(z, 5, 5);
                                long tmp2 = tmp2b - tmp2a;
                                if (tmp2 < 100 || tmp2 > 199) {
                                    continue;
                                }
                                // 第三行
                                long tmp3a = yc * x;
                                if ((tmp3a / 100) != 9 || tmp3a >= 1000) {
                                    continue;
                                }
                                long tmp3b = tmp2 * 10 + getnum(z, 6, 6);
                                long tmp3 = tmp3b - tmp3a;
                                if (tmp3 >= 100) {
                                    continue;
                                }
                                // 第四行
                                long tmp4b = ye * x;
                                if (tmp4b < 1000) {
                                    continue;
                                }
                                long tmp4a = tmp3 * 100 + getnum(z, 7, 8);
                                if (tmp4a == tmp4b) {
                                    System.out.println("x = " + x);
                                    System.out.println("y = " + y);
                                    System.out.println("z = " + z);
                                    System.out.println("结果为 : ");
                                    System.out.println("       " + y);
                                    System.out.println("    --------");
                                    System.out.println(x+"|"+z);
                                    System.out.println("   /"+tmp1a);
                                    System.out.println("   ---------");
                                    System.out.println("     " + tmp2b);
                                    System.out.println("     " + tmp2a);
                                    System.out.println("   ---------");
                                    System.out.println("     " + tmp3b);
                                    System.out.println("      " + tmp3a);
                                    System.out.println("   ---------");
                                    System.out.println("       " + tmp4b);
                                    System.out.println("       " + tmp4a);
                                    System.out.println("   ---------");
                                    System.out.println("          0");
                                } else {
                                    continue;
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}

answer: