sdutoj 分数四则运算

分数四则运算

Time Limit: 1000MS Memory Limit: 65536KB

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。

Example Input

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

Example Output

1/25
-1/4
0
1
1

生敲代码200行

 

import java.util.*;

public class Main {
	public static int gcd(int a, int b)
	{
		return b==0?a:gcd(b, a%b);
	}
	public static void main(String[] args) {
		Scanner cin = new Scanner(System.in);
		while(cin.hasNext())
		{
			String str;
			str = cin.nextLine();
			int s1, s2, t1, t2;
			int i;
			s1 = 0;
			char s = '+';
			int n = str.length();
			for(i = 0; i < n; i++)
			{
				char e;
				e = str.charAt(i);
				if(e == '/')
				{
					i++;
					break;
				}
				else
				{
					s1 = s1*10;
					s1 = s1 + e - '0';
				}
			}
			s2 = 0;
			for(; i < n; i++)
			{
				char e;
				e = str.charAt(i);
				if(e == '*' || e=='-'||e=='+'||e=='\\')
				{
					i++;
					s = e;
					break;
				}
				else
				{
					s2 = s2*10;
					s2 = s2 + e - '0';
				}
			}
			t1 = 0;
			for(; i < n; i++)
			{
				char e;
				e = str.charAt(i);
				if(e == '/')
				{
					i++;
					break;
				}
				else
				{
					t1 = t1*10;
					t1 = t1 + e - '0';
				}
			}
			t2 = 0;
			for(; i < n; i++)
			{
				char e;
				e = str.charAt(i);
				t2 = t2*10;
				t2 = t2 + e - '0';
			}
			//System.out.println(s1+" "+s2+" "+t1+" "+t2);
			if(s == '+')
			{
				s1 = s1*t2+s2*t1;
				s2 = s2*t2;
				int t = gcd(s1, s2);
				if(s2 == 1)
				{
					System.out.println(s1);
				}
				else if(t == 1)
				{
					System.out.println(s1+"/"+s2);
				}
				else
				{
					s1 = s1/t;
					s2 = s2/t;
					if(s2 == 1)
					{
						System.out.println(s1);
					}
					else
					{
						System.out.println(s1+"/"+s2);
					}
				}
			}
			else if(s == '-')
			{
				s1 = s1*t2-s2*t1;
				s2 = s2*t2;
				int f = 1;
				if(s1 < 0)
				{
					s1 = -s1;
					f = -1;
				}
				int t = gcd(s1, s2);
				s1 = s1*f;
				if(s2 == 1)
				{
					System.out.println(s1);
				}
				else if(t == 1)
				{
					System.out.println(s1+"/"+s2);
				}
				else
				{
					s1 = s1/t;
					s2 = s2/t;
					if(s2 == 1)
					{
						System.out.println(s1);
					}
					else
					{
						System.out.println(s1+"/"+s2);
					}
				}
			}
			else if(s == '*')
			{
				s1 = s1*t1;
				s2 = s2*t2;
				int t = gcd(s1, s2);
				if(s2 == 1)
				{
					System.out.println(s1);
				}
				else if(t == 1)
				{
					System.out.println(s1+"/"+s2);
				}
				else
				{
					s1 = s1/t;
					s2 = s2/t;
					if(s2 == 1)
					{
						System.out.println(s1);
					}
					else
					{
						System.out.println(s1+"/"+s2);
					}
				}
			}
			else
			{
				s1 = s1*t2;
				s2 = s2*t1;
				int t = gcd(s1, s2);
				if(s2 == 1)
				{
					System.out.println(s1);
				}
				else if(t == 1)
				{
					System.out.println(s1+"/"+s2);
				}
				else
				{
					
					s1 = s1/t;
					s2 = s2/t;
					if(s2 == 1)
					{
						System.out.println(s1);
					}
					else
					{
						System.out.println(s1+"/"+s2);
					}
				}
			}
		}
	}
}