Lab 8, Exercise 2 Possible Solution

braces.cpp

#include <iostream>
#include <vector>

using namespace std;

bool isStartingBrace(char v) {
    string braces = "[{(";
    return braces.find(v) != -1;
}

bool isEndingBrace(char v) {
    string braces = "]})";
    return braces.find(v) != -1;
}

char oppositeBrace(char v) {
    if (v == '}') {
        return '{';
    } else if (v == ']') {
        return '[';
    } else if (v == ')') {
        return '(';
    }

    cout << "AHHHHHHH!!!!" << endl;
}

bool bracesMatching(string v) {
    vector<char> stack;
    for (int i = 0; i < v.size(); ++i) {
        if (isStartingBrace(v.at(i))) {
            stack.push_back(v.at(i));
        }
        else if (isEndingBrace(v.at(i))) {
            if (stack.size() == 0) {
                return false;
            }

            if (stack.at(stack.size() - 1) != oppositeBrace(v.at(i))) {
                return false;
            }

            stack.pop_back();
        }
    }

    return stack.size() == 0;
}

int main() {
    string str;
    cout << "Enter a string: ";
    cin >> str;

    if (bracesMatching(str)) {
        cout << "matching" << endl;
    } else {
        cout << "not matching" << endl;
    }

    return 0;
}