SDUTOJ 3849 - 分数四则运算

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Problem Description

编写程序，实现两个分数的加减法

Input

输入包含多行数据；

每行数据是一个字符串，格式是"a/boc/d"，其中a, b, c, d为数字（每个数字保证为正数并且不存在正号）。o是运算符"+“或者”-","*",""。

数据以EOF结束，输入数据保证合法。

Output

直接输出结果，并且注意结果应符合书写习惯，没有多余的符号、分子、分母，并且化简至最简分数形式。

Sample Input

1/100+3/100
1/4-1/2
1/3-1/3
1/2*2/1
1/2\1/2

Sample Output

1/25
-1/4
0
1
1

Hint

Source

import java.util.Scanner;

class Op{
    int a, b, c ,d;
    char ch;
    int up_data, down_data;

    Op(int a, int b, int c, int d, char ch){
        this.a = a;
        this.b = b;
        this.c = c;
        this.d = d;
        this.ch = ch;
        Operation();
        Approximate();
    }

    public void Operation(){
        if (ch == '+'){
            down_data = b*d;
            up_data = a*d + c*b;
        }
        else if (ch == '-'){
            down_data = b*d;
            up_data = a*d - c*b;
        }
        else if (ch == '*'){
            up_data = a*c;
            down_data = b*d;
        }
        else{
            up_data = a*d;
            down_data = b*c;
        }
    }

    public void Approximate(){ // 约分即除以最小公倍数
        int m, n;
        int flag = 0;
        if (up_data < 0||down_data < 0){
            flag = 1;
            up_data = Math.abs(up_data);
            down_data = Math.abs(down_data);
        }
        if (up_data > down_data){
            m = up_data;
            n = down_data;
        }
        else{
            m = down_data;
            n = up_data;
        }
        while(n > 0){
            int temp = m%n;
            m = n;
            n = temp;
        }
        up_data /= m;
        down_data /= m;
        if (flag == 1){
            up_data = -up_data;
        }
    }
}

class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()){
            String str = sc.nextLine();
            char ch = '0';
            for (int i = 0; i < str.length(); i++) {
                if (str.charAt(i) == '+'){
                    ch = '+';
                }
                else if (str.charAt(i) == '-'){
                    ch = '-';
                }
                else if (str.charAt(i) == '*'){
                    ch = '*';
                }
                else if (str.charAt(i) == '\\'){
                    ch = '\\';
                }
            }
            String[] num = str.split("/|-|\\+|\\*|\\\\"); // 转义字符的分割；多个分割符分割
            int a = Integer.parseInt(num[0]);
            int b = Integer.parseInt(num[1]);
            int c = Integer.parseInt(num[2]);
            int d = Integer.parseInt(num[3]);
            Op nb = new Op(a,b,c,d,ch);
            if (nb.up_data == 0){
                System.out.println(0);
            }
            else if (nb.up_data == nb.down_data){
                System.out.println(1);
            }
            else{
                System.out.println(nb.up_data+"/"+nb.down_data);
            }
        }
    }
}