20165221----第二届构建之法论坛学习总结

配置环境

配置JDK

我选择在Windows中配置
！
按照教程，进行环境变量的配置。
因为我将安装的jdk放在D-jdk1.8-java中，所以按如下方式配置编辑path变量。
此时jdk安装和配置完成！

下载IDE

克隆项目

先进行注册，用户名设置为学号20165221,邮箱为自己的QQ邮箱876812128@qq.com注册成功界面如下
然后进行登录
查看登录信息
在git命令行找到操作地址
阿超的代码

import java.util.Stack;

public class Main {

    private static String[] op = { "+", "-", "*", "/" };// Operation set
    public static void main(String[] args) {
        String question = MakeFormula();
        System.out.println(question);
        String ret = Solve(question);
        System.out.println(ret);
    }

    public static String MakeFormula(){
        StringBuilder build = new StringBuilder();
        int count = (int) (Math.random() * 2) + 1; // generate random count
        int start = 0;
        int number1 = (int) (Math.random() * 99) + 1;
        build.append(number1);
        while (start <= count){
            int operation = (int) (Math.random() * 3); // generate operator
            int number2 = (int) (Math.random() * 99) + 1;
            build.append(op[operation]).append(number2);
            start ++;
        }
        return build.toString();
    }

    public static String Solve(String formula){
        Stack<String> tempStack = new Stack<>();//Store number or operator
        Stack<Character> operatorStack = new Stack<>();//Store operator
        int len = formula.length();
        int k = 0;
        for(int j = -1; j < len - 1; j++){
            char formulaChar = formula.charAt(j + 1);
            if(j == len - 2 || formulaChar == '+' || formulaChar == '-' || formulaChar == '/' || formulaChar == '*') {
                if (j == len - 2) {
                    tempStack.push(formula.substring(k));
                }
                else {
                    if(k < j){
                        tempStack.push(formula.substring(k, j + 1));
                    }
                    if(operatorStack.empty()){
                        operatorStack.push(formulaChar); //if operatorStack is empty, store it
                    }else{
                        char stackChar = operatorStack.peek();
                        if ((stackChar == '+' || stackChar == '-')
                                && (formulaChar == '*' || formulaChar == '/')){
                            operatorStack.push(formulaChar);
                        }else {
                            tempStack.push(operatorStack.pop().toString());
                            operatorStack.push(formulaChar);
                        }
                    }
                }
                k = j + 2;
            }
        }
        while (!operatorStack.empty()){ // Append remaining operators
            tempStack.push(operatorStack.pop().toString());
        }
        Stack<String> calcStack = new Stack<>();
        for(String peekChar : tempStack){ // Reverse traversing of stack
            if(!peekChar.equals("+") && !peekChar.equals("-") && !peekChar.equals("/") && !peekChar.equals("*")) {
                calcStack.push(peekChar); // Push number to stack
            }else{
                int a1 = 0;
                int b1 = 0;
                if(!calcStack.empty()){
                    b1 = Integer.parseInt(calcStack.pop());
                }
                if(!calcStack.empty()){
                    a1 = Integer.parseInt(calcStack.pop());
                }
                switch (peekChar) {
                    case "+":
                        calcStack.push(String.valueOf(a1 + b1));
                        break;
                    case "-":
                        calcStack.push(String.valueOf(a1 - b1));
                        break;
                    case "*":
                        calcStack.push(String.valueOf(a1 * b1));
                        break;
                    default:
                        calcStack.push(String.valueOf(a1 / b1));
                        break;
                }
            }
        }
        return formula + "=" + calcStack.pop();
    }
}