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);
          }
        }
      }
    }
  }
}