讀檔&2個分數加減乘除

Q8分數加減乘除.java

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

// 2個分數加減乘除
public class Q940308 {
	public static void main(String[] args) throws IOException{
		String fileName = "940308.SM";
		FileReader fr = new FileReader(fileName);
		BufferedReader br = new BufferedReader(fr);
		
		String s;
		while ((s=br.readLine())!=null && s.length()>0){
			String[] tmp = s.split(",");
			tmp[2] = tmp[2].trim();
			int num1s=Integer.parseInt(tmp[0].trim());
			int num1p=Integer.parseInt(tmp[1].trim());
			int num2s=Integer.parseInt(tmp[3].trim());
			int num2p=Integer.parseInt(tmp[4].trim());
			System.out.print(num1s+"/"+num1p+" "+tmp[2]+" "+num2s+"/"+num2p+" = ");
			switch(tmp[2]){
				case "+":
					System.out.println(plus(num1s,num1p,num2s,num2p));
					break;
				case "-":
					System.out.println(minus(num1s,num1p,num2s,num2p));
					break;
				case "*":
					System.out.println(mul(num1s,num1p,num2s,num2p));
					break;
				case "/":
					System.out.println(div(num1s,num1p,num2s,num2p));
					break;
			}
		}
		
		fr.close();
	}
	
	// 加法
	public static String plus(int num1s, int num1p, int num2s, int num2p){
		int news = num1s*num2p+num1p*num2s;
		int newp = num1p*num2p;
		return simple(news, newp);
	}
	
	// 減法
	public static String minus(int num1s, int num1p, int num2s, int num2p){
		int news = num1s*num2p-num1p*num2s;
		int newp = num1p*num2p;
		return simple(news, newp);
	}
	
	// 乘法
	public static String mul(int num1s, int num1p, int num2s, int num2p){
		int news = num1s*num2s;
		int newp = num1p*num2p;
		return simple(news, newp);
	}
	
	// 除法
	public static String div(int num1s, int num1p, int num2s, int num2p){
		int news = num1s*num2p;
		int newp = num1p*num2s;
		return simple(news, newp);
	}
	// 約分
	public static String simple(int s,int p){
		if (s==p) return "1";
		if (s==0) return "0";
		for (int i=2; i<s; i++)
			if (s%i==0 && p%i==0){
				s/=i;
				p/=i;
			}
		return String.valueOf(s)+"/"+String.valueOf(p);
	}
}