Upgraded Balanced Parentheses using C++

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

using namespace std;

int main() {
    string x;
    stack < char, vector<char> > iStack;
    cout << "Enter series of parentheses: ";
    getline(cin, x);
    char ch;
    int cnt = 0;
    for (int i = 0; i < x.length(); i++) {
        if (x[i] == '(' || x[i] == '{' || x[i] == '[') {
            cnt++;
            iStack.push(x[i]);
        } else {
            if (iStack.empty()) {
                break;
            }
            if (x[i] == ')') {
                if (iStack.top() == '(') {
                    cnt++;
                    iStack.pop();
                }
            } else if (x[i] == '}') {
                if (iStack.top() == '{') {
                    cnt++;
                    iStack.pop();
                }
            } else if (x[i] == ']') {
                if (iStack.top() == '[') {
                    cnt++;
                    iStack.pop();
                }
            }
        }
    }
    if (iStack.empty() && cnt == (int) x.size()) {
        cout << "Balance!" << endl;
    } else {
        cout << "Not Balance!" << endl;
    }
    return 0;
}