个人开发

时间：2021-04-12 12:51:46 收藏：0 阅读：0
ackage chapter;
 
import java.util.ArrayList;
import java.util.List;
import java.util.Stack;
 
public class Master {
    private static String[] op = { "+", "-", "*", "/" };
 
 
    public static List<String> returnUserInNum(int a){
         List<String> ac=new ArrayList();
        int i=1;
        while(i<=a){
             String question=MakeFormula();
             ac.add(question);
             i++;
        }
       return ac;
    }
    //算式
    public static String MakeFormula(){
        StringBuilder build = new StringBuilder();
        int count = (int) (Math.random() * 2) + 1; // 生成1-3之间的随机整数（不包括3）
        int start = 0;
        int number1 = (int) (Math.random() * 99) + 1;//生成1-100之间的随机整数（不包括100）
        build.append(number1);
        while (start <= count){
            int operation = (int) (Math.random() * 3); //生成0-3之间的随机整数（不包括3）
            int number2 = (int) (Math.random() * 99) + 1;//生成1-100之间的随机整数（不包括100）
            build.append(op[operation]).append(number2);
            start ++;
        }
        return build.toString();
    }
 
    public static String Solve(String formula){
        Stack<String> tempStack = new Stack<>();
        Stack<Character> operatorStack = new Stack<>();
        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);
                    }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()){
            tempStack.push(operatorStack.pop().toString());
        }
        Stack<String> calcStack = new Stack<>();
        for(String peekChar : tempStack){
            if(!peekChar.equals("+") && !peekChar.equals("-") && !peekChar.equals("/") && !peekChar.equals("*")) {
                calcStack.push(peekChar);
            }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();