C++ 中缀表达式转后缀表达式

#include 
#include 
#include 

using namespace std;

bool isPrior(char ch1, char ch2)
{
    if(ch1 == '(' || ch2 == '(')
    {
        return true;
    }
    if((ch1 == '*' || ch1 == '/') && (ch2 == '+' || ch2 == '-'))
    {
        return true;
    }

    return false;
};

vector<char> infixToPostfix(vector<char> infixExpression)
{
    vector<char> postfixExpression;
    stack<char> operators;

    for(char ch : infixExpression)
    {
        if(ch >= '0' && ch <= '9')
        {
            postfixExpression.push_back(ch);
        }
        else
        {
            if(operators.empty() || isPrior(ch, operators.top()))
            {
                operators.push(ch);
            }
            else if(ch == ')')
            {
                while(operators.top() != '(')
                {
                    postfixExpression.push_back(operators.top());
                    operators.pop();
                }
                operators.pop();
            }
            else
            {
                while(!operators.empty() && !isPrior(ch, operators.top()))
                {
                    postfixExpression.push_back(operators.top());
                    operators.pop();
                }
                operators.push(ch);
            }
        }
    }

    while(!operators.empty())
    {
        postfixExpression.push_back(operators.top());
        operators.pop();
    }

    return postfixExpression;
};

int computePostfixExpression(vector<char> postfixExpression)
{
    stack<int> operands;
    int leftOperand, rightOperand;

    for(char ch : postfixExpression)
    {
        if (ch >= '0' && ch <= '9')
        {
            operands.push(ch - '0');
        }
        else
        {
            rightOperand = operands.top();
            operands.pop();
            leftOperand = operands.top();
            operands.pop();

            switch (ch)
            {
                case '+' :
                    operands.push(leftOperand + rightOperand);
                    break;
                case '-' :
                    operands.push(leftOperand - rightOperand);
                    break;
                case '*' :
                    operands.push(leftOperand * rightOperand);
                    break;
                case '/' :
                    operands.push(leftOperand / rightOperand);
                    break;
            }
        }
    }
    return operands.top();
};
int main()
{
    vector<char> infixExpression{'(', '(', '2', '+', '3', ')', '*', '8', '+', '5', '+', '6', ')', '*', '6'};
    
    cout << computePostfixExpression(infixToPostfix(infixExpression)) << endl;

    return 0;;
}