Question

是的！感谢上一个问题的帮助！对于指定的字符串方程，它完美地工作！但是现在我遇到两个括号（无论是打开还是关闭）在一起时遇到麻烦

示例：4+（2+（1 + 1））

在我的代码的某处，它被困在一个循环中，但我不知道在哪里！怎么了？我的代码：

import java.util.ArrayList;

public class StringEquation
{
    public static void main(String[] args) 
    {
        String s = "2+(8*(7+1))";

        ArrayList<String> equation = new ArrayList<>();

        String ns = "";

        String b;

        int nsi = 0;

        double n;

        double res;

        for(int c=0; c<s.length(); c++)
        {
             b = s.substring(c,c+1);
             if("0".equals(b)||"1".equals(b)||"2".equals(b)||"3".equals(b)||"4".equals(b)||"5".equals(b)||"6".equals(b)||"7".equals(b)||"8".equals(b)||"9".equals(b))
             {
                 ns += b;
                 if(c==s.length()-1)
                 {
                     nsi = Integer.parseInt(ns);
                     equation.add(Integer.toString(nsi));
                 }
             }
             else if(("+".equals(b)||"-".equals(b)||"*".equals(b)||"/".equals(b)||"%".equals(b))&&!"".equals(ns))
             {
                nsi = Integer.parseInt(ns);
                equation.add(Integer.toString(nsi));
                equation.add(b);
                ns = "";
             }
             else if("(".equals(b))
             {
                 equation.add(b);
             }
             else if (")".equals(b))
             {
                if(!"".equals(ns))
                {
                    nsi = Integer.parseInt(ns);
                }
                equation.add(Integer.toString(nsi));
                equation.add(b);
                ns = "";
             }
             else if("+".equals(b)||"-".equals(b)||"*".equals(b)||"/".equals(b)||"%".equals(b))
             {
                 equation.add(b);
             }
        }

        while(equation.contains("(")||equation.contains(")"))
        {
            for(int d=0; d<equation.size(); d++)
            {
                if("*".equals(equation.get(d))||"/".equals(equation.get(d))||"%".equals(equation.get(d)))
                {
                    if("(".equals(equation.get(d-1))||")".equals(equation.get(d-1))||"(".equals(equation.get(d+1))||")".equals(equation.get(d+1)))
                    {
                        switch(equation.get(d))
                        {
                            case "*": equation.set(d, "TIMES"); break;
                            case "/": equation.set(d, "DIVBY"); break;
                            default: equation.set(d, "MOD");
                        }
                    }
                    else
                    {
                        switch(equation.get(d))
                        {
                            case "*":
                                n = Double.parseDouble(equation.get(d-1));
                                n *= Double.parseDouble(equation.get(d+1));
                                equation.set(d-1, Double.toString(n));
                                equation.remove(d);
                                equation.remove(d);
                                break;
                            case "/":
                                n = Double.parseDouble(equation.get(d-1));
                                n /= Double.parseDouble(equation.get(d+1));
                                equation.set(d-1, Double.toString(n));
                                equation.remove(d);
                                equation.remove(d);
                                break;
                            default:
                                n = Double.parseDouble(equation.get(d-1));
                                n %= Double.parseDouble(equation.get(d+1));
                                equation.set(d-1, Double.toString(n));
                                equation.remove(d);
                                equation.remove(d);
                        }
                    }
                }
            }

            for(int d=0; d<equation.size(); d++)
            {
                if("+".equals(equation.get(d))||"-".equals(equation.get(d)))
                {
                    if("(".equals(equation.get(d-1))||")".equals(equation.get(d-1))||"(".equals(equation.get(d+1))||")".equals(equation.get(d+1)))
                    {
                        switch(equation.get(d))
                        {
                            case "+": equation.set(d, "PLUS"); break;
                            default: equation.set(d, "MINUS");
                        }
                    }
                    else
                    {
                        switch(equation.get(d))
                        {
                            case "+":
                                n = Double.parseDouble(equation.get(d-1));
                                n += Double.parseDouble(equation.get(d+1));
                                equation.set(d-1, Double.toString(n));
                                equation.remove(d);
                                equation.remove(d);
                                break;
                            default:
                                n = Double.parseDouble(equation.get(d-1));
                                n -= Double.parseDouble(equation.get(d+1));
                                equation.set(d-1, Double.toString(n));
                                equation.remove(d);
                                equation.remove(d);
                        }
                    }
                }
            }

            for(int d=0; d<equation.size(); d++)
            {
                switch(equation.get(d))
                {
                    case "PLUS":    equation.set(d, "+"); break;
                    case "MINUS":   equation.set(d, "-"); break;
                    case "TIMES":   equation.set(d, "*"); break;
                    case "DIVBY":   equation.set(d, "/"); break;
                    case "MOD":     equation.set(d, "%"); break;
                }
            }

            for(int d=0; d<equation.size(); d++)
            {
                if(d>0)
                {
                    if("(".equals(equation.get(d-1))&&")".equals(equation.get(d+1)))
                    {
                        equation.remove(d-1);
                        equation.remove(d);
                    }
                }
            }
        }

        for(int d=0; d<equation.size(); d++)
        {
            if("*".equals(equation.get(d))||"/".equals(equation.get(d))||"%".equals(equation.get(d)))
            {
                switch(equation.get(d))
                {
                    case "*":
                        n = Double.parseDouble(equation.get(d-1));
                        n *= Double.parseDouble(equation.get(d+1));
                        equation.set(d-1, Double.toString(n));
                        equation.remove(d);
                        equation.remove(d);
                        break;
                    case "/":
                        n = Double.parseDouble(equation.get(d-1));
                        n /= Double.parseDouble(equation.get(d+1));
                        equation.set(d-1, Double.toString(n));
                        equation.remove(d);
                        equation.remove(d);
                        break;
                    default:
                        n = Double.parseDouble(equation.get(d-1));
                        n %= Double.parseDouble(equation.get(d+1));
                        equation.set(d-1, Double.toString(n));
                        equation.remove(d);
                        equation.remove(d);
                }
            }
        }

        for(int d=0; d<equation.size(); d++)
        {
            if("+".equals(equation.get(d))||"-".equals(equation.get(d)))
            {
                switch(equation.get(d))
                {
                    case "+":
                        n = Double.parseDouble(equation.get(d-1));
                        n += Double.parseDouble(equation.get(d+1));
                        equation.set(d-1, Double.toString(n));
                        equation.remove(d);
                        equation.remove(d);
                        break;
                    default:
                        n = Double.parseDouble(equation.get(d-1));
                        n -= Double.parseDouble(equation.get(d+1));
                        equation.set(d-1, Double.toString(n));
                        equation.remove(d);
                        equation.remove(d);
                }
            }
        }

        res = Double.parseDouble(equation.get(0));

        System.out.println(res);

    }
}

Answer 1

从字符串中删除所有额外的元素说“（”“）”并将数字和符号放在单独的队列中，然后从队列中获取每个元素，同时继续检查天气它是否为数字，如果它是数字将下一个元素作为符号

简单到复数方程的弦方程（2）

1 个答案: