java-计算24点

import java.util.Scanner;

/**
* Created on 2016/6/19.
*/
public class TwentyFourCalculate {

public static void main(String[] args)throws Exception{
Scanner s = new Scanner(System.in);
// 输入abcd四个数
System.out.println("请依次输入四个0-9的整数，不限顺序，可以重复,按回车键确认输入");
System.out.println("请输入第一个整数：");
int a = s.nextInt();
System.out.println("您输入第一个整数：" + a);
System.out.println("请输入第二个整数：");
int b = s.nextInt();
System.out.println("您输入第二个整数：" + b);
System.out.println("请输入第三个整数：");
int c = s.nextInt();
System.out.println("您输入第三个整数：" + c);
System.out.println("请输入第四个整数：");
int d = s.nextInt();
System.out.println("您输入第四个整数：" + d);
System.out.println("将计算出所有可以算出24的结果:");
Thread.sleep(3000);


int[] num = new int[4];
num[0] = a;
num[1] = b;
num[2] = c;
num[3] = d;
// 将4个数的不同顺序组合去碰撞试24点计算
permutationNumber(num);
System.out.println("已列出所有結果！");
}

// 打印出计算
public static void permutationNumber(int[] num) {
//计算的数字排列为 4*3*2*1 种
//举出所以的组合，将答案为24的打印出
for (int i = 0; i < num.length; i++) {
for (int j = 0; j < num.length; j++) {
for (int k = 0; k < num.length; k++) {
for (int l = 0; l < num.length; l++) {
if (i == j || i == k || i == l || j == k || j == l || k == l) {
continue;
}
sequence(num[i], num[j], num[k], num[l]);
}
}
}
}
}

// a mark1 b mark2 c mark3 d 的 计算顺序和不同+-*/的各种组合
// 计算形式为 +-*/ 四种
// 计算的顺序为 （（1#2）#3）#4、（1#2）#（3#4）、（1#（2#3））#4、1#（（2#3）#4）、1#（2#（3#4）） 五种
public static void sequence(double a, double b, double c, double d) {
// 第一个运算符4种
for (int mark1 = 1; mark1 <= 4; mark1++) {
// 第二个运算符4种
for (int mark2 = 1; mark2 <= 4; mark2++) {
// 第三个运算符4种
for (int mark3 = 1; mark3 <= 4; mark3++) {
// 五种计算顺序类型
for (int type = 1; type <= 5; type++) {
double result = 0;
switch (type) {
case 1:
// ((a mark1 b)mark2 c) mark3 d 形

式
result = calculate(calculate(calculate(a, b, mark1), c, mark2), d, mark3);
if (result == 24) {
System.out.println("((" + a + getMarkString(mark1) + b + ")" + getMarkString(mark2) + c + ")" + getMarkString(mark3) + d);
}
break;
case 2:
// (a mark1 b)mark2 (c mark3 d )形式
result = calculate(calculate(a, b, mark1), calculate(c, d, mark3), mark2);
if (result == 24) {
System.out.println("(" + a + getMarkString(mark1) + b + ")" + getMarkString(mark2) + "(" + c + getMarkString(mark3) + d + ")");
}
break;
case 3:
// (a mark1 (b mark2 c)) mark3 d 形式
result = calculate(calculate(a, calculate(b, c, mark2), mark1), d, mark3);
if (result == 24) {
System.out.println("(" + a + getMarkString(mark1) + "(" + b + getMarkString(mark2) + c + "))" + getMarkString(mark3) + d);
}
break;
case 4:
// a mark1 ((b mark2 c) mark3 d) 形式
result = calculate(a, calculate(calculate(b, c, mark2), d, mark3), mark1);
if (result == 24) {
System.out.println("((" + a + getMarkString(mark1) + "((" + b + getMarkString(mark2) + c + ")" + getMarkString(mark3) + d + ")");
}
break;
case 5:
// a mark1 (b mark2 (c mark3 d)) 形式
result = calculate(a, calculate(b, calculate(c, d, mark3), mark2), mark1);
if (result == 24) {
System.out.println("((" + a + getMarkString(mark1) + "(" + b + getMarkString(mark2) + "(" + c + getMarkString(mark3) + d + "))");
}
break;
default:
break;
}
}

}
}
}
}

// 数字计算，first mark second
// 其中markType(1:+;2:-;3:*;4:/)
public static double calculate(double first, double second, int markType) {
switch (markType) {
case 1:
return first + second;
case 2:
return first - second;
case 3:
return first * second;

case 4:
return first / second;
default:
return 0;
}
}

// 打印时候判定运算符
// 其中markType(1:+;2:-;3:*;4:/)
public static String getMarkString(int markType) {
switch (markType) {
case 1:
return "+";
case 2:
return "-";
case 3:
return "*";
case 4:
return "/";
default:
return " ";
}
}


}