c++基于栈的中缀表达式

以下是C++基于栈的中缀表达式求值的示例代码：

#include <iostream>
#include <stack>
#include <string>

using namespace std;

// 定义运算符优先级
int priority(char op) {
    if (op == '+' || op == '-') {
        return 1;
    } else if (op == '*' || op == '/') {
        return 2;
    } else {
        return 0;
    }
}

// 中缀表达式转后缀表达式
string infixToPostfix(string infix) {
    stack<char> s;
    string postfix = "";
    for (int i = 0; i < infix.length(); i++) {
        char c = infix[i];
        if (isdigit(c)) {
            postfix += c;
        } else if (c == '(') {
            s.push(c);
        } else if (c == ')') {
            while (!s.empty() && s.top() != '(') {
                postfix += s.top();
                s.pop();
            }
            s.pop();
        } else {
            while (!s.empty() && priority(s.top()) >= priority(c)) {
                postfix += s.top();
                s.pop();
            }
            s.push(c);
        }
    }
    while (!s.empty()) {
        postfix += s.top();
        s.pop();
    }
    return postfix;
}

// 计算后缀表达式的值
int evaluatePostfix(string postfix) {
    stack<int> s;
    for (int i = 0; i < postfix.length(); i++) {
        char c = postfix[i];
        if (isdigit(c)) {
            s.push(c - '0');
        } else {
            int operand2 = s.top();
            s.pop();
            int operand1 = s.top();
            s.pop();
            switch (c) {
                case '+':
                    s.push(operand1 + operand2);
                    break;
                case '-':
                    s.push(operand1 - operand2);
                    break;
                case '*':
                    s.push(operand1 * operand2);
                    break;
                case '/':
                    s.push(operand1 / operand2);
                    break;
            }
        }
    }
    return s.top();
}

int main() {
    string infix = "1+(2-3)*4+10/5";
    string postfix = infixToPostfix(infix);
    cout << "Postfix expression: " << postfix << endl;
    int result = evaluatePostfix(postfix);
    cout << "Result: " << result << endl;
    return 0;
}