多项式 Wannafly挑战赛22

后缀表达式 大整数(加法、乘法、gcd java)

import java.math.BigInteger;
import java.util.Scanner;
 
class Work {
    String str;
    int _num,_sym;
    int []sym=new int[1000];
    BigInteger []num=new BigInteger[1000];
    int []w=new int[1000];
     
    Work() {
        BigInteger x,y;
        int wx,wy;
        Scanner in=new Scanner(System.in);
        str=in.nextLine();
        work();
        x=num[1];
        wx=w[1];
        str=in.nextLine();
        work();
        y=num[1];
        wy=w[1];
         
        if (wx>wy)
            System.out.println("1/0");
        else if (wx<wy)
            System.out.println("0/1");
        else
        {
            BigInteger z;
            z=x.gcd(y);
            x=x.divide(z);
            y=y.divide(z);
            System.out.print(x+"/"+y);
        }
        in.close();
    }
     
    void cal()
    {
        if (sym[_sym]==2)
        {
            if (w[_num-1]<w[_num])
            {
                w[_num-1]=w[_num];
                num[_num-1]=num[_num];
            }
            else if (w[_num-1]==w[_num])
                num[_num-1]=num[_num-1].add(num[_num]);
        }
        else if (sym[_sym]==3)
        {
            w[_num-1]+=w[_num];
            num[_num-1]=num[_num-1].multiply(num[_num]);
        }
        _sym--;
        _num--;
    }
     
    void work()
    {
        int len,i;
        BigInteger z;
        len=str.length();
        z=BigInteger.valueOf(1);
        _num=0;
        _sym=0;
        sym[0]=0;
      
        for (i=0;i<len;i++)
        {
            if (str.charAt(i)=='x')
            {
                num[++_num]=z;
                w[_num]=1;
            }
            else
            {
                switch(str.charAt(i))
                {
                    case '+':
                        while (sym[_sym]>=2)
                            cal();
                        sym[++_sym]=2;
                        break;
                    case '*':
                        while (sym[_sym]>=3)
                            cal();
                        sym[++_sym]=3;
                        break;
                    case '(':
                        sym[++_sym]=1;
                        break;
                    case ')':
                        while (sym[_sym]!=1)
                            cal();
                        _sym--;
                        break;
                }
            }
        }
        while (_sym>0)
            cal();
    }
}
 
public class Main {
    public static void main(String[] args) {
        Work work=new Work();
    }
}