在C ++中使用堆栈模板类解析括号

我有一个作业，并且在最近的两天里一直在窃听，我一直在做伪代码，但仍然没有正确。例如，如果我输入“ mike]”或“ mike] 123”，则由于堆栈为空，我的程序将崩溃...根据我的观察，以下情况该程序将崩溃：-堆栈为空-并且有一个简短的括号PS：在us2012的帮助下，我可以解决崩溃问题。但是，结果不正确。而不是打印出“无效”，它输出“有效”

:(

这是我教授的伪代码：

def parse_parenthesis(str):
    stack = create a new empty stack of OpenParen objects
    for i from 0 to str.size() - 1:
        if str[i] is an open parenthesis
            stack.push(new OpenParen(str[i]))
        else if str[i] is not a close parenthesis:
            # str[i] is not a parenthesis of any kind, so ignore it
            continue
        # otherwise str[i] must be a close parenthesis, try to
        # match it with the most recent open paren, on the top
        # of the stack
        else if stack is empty
        return false;
        else if stack.peek() is of the same type as str[i]:
        # close properly
        stack.pop()
        else
        return false;
    if stack is not empty
        return false;
    else
        return true

这是我到目前为止所拥有的：

.cpp文件

bool ParenMatching(const string& s, unique_ptr<string>& output)
{
    unique_ptr<OpenParen> stack(new OpenParen);

    bool validOpen, validClose, valid;
    bool match; //haveCloseParen;
    /*string unMatch = "Unmatch";
    string unExpected = "Unexpected close paren";
    string noError = "No Error";*/

    for (size_t i = 0; i < s.length(); i++)
    {
        // check if its open parenthesis
        validOpen = stack->IsOpenParen(s[i]);
        // check if its close parenthesis
        validClose = stack->IsCloseParen(s[i]);

        // if there is open paren, push into the stack
        if(validOpen)
            stack->PushObj(s[i]);
        else if(!validClose)
        {
            continue;
        }
            else if(stack->GetObj().IsEmpty())
            valid = false;      
        else if(match = IsMatchParen(s[i], stack))
            stack->PopObj();            
        else
            valid = false;
    }

    if(!stack->GetObj().IsEmpty())
        valid = false;
    else
        valid = true;
    return valid;
}

bool IsMatchParen(const char c, const unique_ptr<OpenParen>& stack)
{   
    bool valid;
    if(c == ')' && stack->PeekObj() == '(')
        valid = true;
    else if (c == ']' && stack->PeekObj() == '[')
        valid = true;
    else if (c == '}' && stack->PeekObj() == '{')
        valid = true;
    else if (c == '>' && stack->PeekObj() == '<')
        valid = true;
    else
        valid = false;
    return valid;
}

OpenParen.cpp

// Check if its open paren
bool OpenParen::IsOpenParen(const char c)
{
    bool isOpen;
    if(c == '(' || c == '[' || c == '{' || c == '<')
        isOpen = true;
    else
        isOpen = false;
    return isOpen;
}

// check if its close paren
bool OpenParen::IsCloseParen(const char c)
{
    bool isClose;
    if(c == ')' || c == ']' || c == '}' || c == '>')
        isClose = true;
    else
        isClose = false;
    return isClose;
}