数据结构课程设计表达式计算java完整代码

以下是基于栈的表达式计算Java代码：

import java.util.Stack;

public class ExpressionCalculator {
    
    // 判断是否为运算符
    private static boolean isOperator(char ch) {
        return ch == '+' || ch == '-' || ch == '*' || ch == '/';
    }
    
    // 计算两个数的结果
    private static double calculate(double a, double b, char operator) {
        switch (operator) {
            case '+':
                return a + b;
            case '-':
                return a - b;
            case '*':
                return a * b;
            case '/':
                return a / b;
            default:
                return 0;
        }
    }
    
    // 计算表达式的值
    public static double evaluate(String expression) {
        Stack<Double> operands = new Stack<>();
        Stack<Character> operators = new Stack<>();
        
        for (int i = 0; i < expression.length(); i++) {
            char ch = expression.charAt(i);
            
            if (Character.isDigit(ch)) { // 如果是数字
                double num = ch - '0';
                while (i + 1 < expression.length() && Character.isDigit(expression.charAt(i + 1))) {
                    num = num * 10 + expression.charAt(++i) - '0';
                }
                operands.push(num);
            } else if (isOperator(ch)) { // 如果是运算符
                while (!operators.isEmpty() && operators.peek() != '(' && (ch != '*' && ch != '/') || (ch == '*' || ch == '/') && (operators.peek() == '*' || operators.peek() == '/')) {
                    double b = operands.pop();
                    double a = operands.pop();
                    char operator = operators.pop();
                    operands.push(calculate(a, b, operator));
                }
                operators.push(ch);
            } else if (ch == '(') { // 如果是左括号
                operators.push(ch);
            } else if (ch == ')') { // 如果是右括号
                while (operators.peek() != '(') {
                    double b = operands.pop();
                    double a = operands.pop();
                    char operator = operators.pop();
                    operands.push(calculate(a, b, operator));
                }
                operators.pop();
            }
        }
        
        while (!operators.isEmpty()) { // 处理剩余的运算符和操作数
            double b = operands.pop();
            double a = operands.pop();
            char operator = operators.pop();
            operands.push(calculate(a, b, operator));
        }
        
        return operands.pop();
    }
    
    public static void main(String[] args) {
        String expression = "2*(3+5)/4-1";
        double result = evaluate(expression);
        System.out.println(expression + " = " + result);
    }
}

该代码实现了基本的四则运算，包括加、减、乘、除和括号。其中使用两个栈分别存储操作数和运算符。在遍历表达式时，如果遇到数字则入栈操作数栈，如果遇到运算符则进行运算，将结果入栈操作数栈。最终得到的操作数栈中只剩下一个元素，即为表达式的值。