带括号的多位数带小数运算计算器c++代码

以下是一个简单的带括号的多位数带小数运算计算器的C++代码：

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

using namespace std;

int priority(char op) {
    if (op == '+' || op == '-') {
        return 1;
    } else if (op == '*' || op == '/') {
        return 2;
    } else {
        return 0;
    }
}

double calculate(double a, double b, char op) {
    if (op == '+') {
        return a + b;
    } else if (op == '-') {
        return a - b;
    } else if (op == '*') {
        return a * b;
    } else if (op == '/') {
        return a / b;
    } else {
        return 0;
    }
}

double calculateExpression(const string& expr) {
    stack<double> numStack;
    stack<char> opStack;
    vector<double> nums;
    vector<char> ops;
    int len = expr.length();
    for (int i = 0; i < len; i++) {
        char c = expr[i];
        if (c == '(') {
            opStack.push(c);
        } else if (c == ')') {
            while (opStack.top() != '(') {
                char op = opStack.top();
                opStack.pop();
                double b = numStack.top();
                numStack.pop();
                double a = numStack.top();
                numStack.pop();
                double res = calculate(a, b, op);
                numStack.push(res);
            }
            opStack.pop();
        } else if (c >= '0' && c <= '9') {
            double num = 0;
            int j = i;
            while (j < len && expr[j] >= '0' && expr[j] <= '9') {
                num = num * 10 + (expr[j] - '0');
                j++;
            }
            if (j < len && expr[j] == '.') {
                double k = 1;
                j++;
                while (j < len && expr[j] >= '0' && expr[j] <= '9') {
                    k = k / 10;
                    num += k * (expr[j] - '0');
                    j++;
                }
            }
            numStack.push(num);
            i = j - 1;
        } else {
            while (!opStack.empty() && opStack.top() != '(' && priority(opStack.top()) >= priority(c)) {
                char op = opStack.top();
                opStack.pop();
                double b = numStack.top();
                numStack.pop();
                double a = numStack.top();
                numStack.pop();
                double res = calculate(a, b, op);
                numStack.push(res);
            }
            opStack.push(c);
        }
    }
    while (!opStack.empty()) {
        char op = opStack.top();
        opStack.pop();
        double b = numStack.top();
        numStack.pop();
        double a = numStack.top();
        numStack.pop();
        double res = calculate(a, b, op);
        numStack.push(res);
    }
    return numStack.top();
}

int main() {
    string expr;
    cout << "请输入带括号的多位数带小数运算表达式：";
    cin >> expr;
    double res = calculateExpression(expr);
    cout << "结果为：" << res << endl;
    return 0;
}

该计算器支持加、减、乘、除四种基本运算，以及带括号的多位数带小数运算。例如，输入表达式 "2*(3+4.5)-5/2"，输出结果为 "12.5"。