практика_стек_6

#include <stack> //1 вариант
#include <string>
#include <fstream>

using namespace std;

int main()
{
    ifstream in("input.txt");
    ofstream out("output.txt");

    stack <char> b;
    string brackets = "()[]{}";
    string tmp;
    getline(in,tmp);
    in.close();
    char a;
    int k = 0;
    for(int i = 0; i < (int)tmp.length(); i++)
    {
        a = tmp[i];
        if (brackets.find(a) % 2 == 0)
            b.push(a);
        else if ( b.empty())
        {
            out << "Not" << endl;
            k++;
            break;
        }
        else if ( b.top() != brackets [brackets.find(a) - 1])
        {
            out << "Not" << endl;
            k++;
            break;
        }
        else b.pop();
    }
   if(k == 0)
    if(b.empty())
        out << "Yes" << endl;
    out.close();
    return 0;
}

// 2 вариант
#include <stack>
#include <string>
#include <fstream>

using namespace std;

int main()
{
    ifstream in("input.txt");
    ofstream out("output.txt");

    stack <char> b;
    string brackets = "()[]{}";
    char a;
    int k =0;
    while(in.peek() != EOF)
    {
        in >> a;
        if (brackets.find(a) % 2 == 0)
            b.push(a);
        else if ( b.empty())
    {
            out << "Not" << endl;
        k++;
        break;
    }
        else if ( b.top() != brackets [brackets.find(a) - 1])
    {
                out << "Not" << endl;
        k++;
        break;
    }
        else b.pop();
    }
    if(k == 0)
    if(b.empty())
        out << "Yes" << endl;



    in.close();
    out.close();

    return 0;
}