gistfile1.cpp

#include <bits/stdc++.h>
using namespace std;

#define int long int

bool check[10001][10001];
main()
{
    int n;
    char command;
    string str;
    int length = 0;
    int ans = 0;
    cin >> n;
    for (int i = 0; i < n; i++)
    // for each command
    {
        cin >> command;

        if (command != '-')
        // if command = push_back
        {
            ans++;
            // at least a palindromic substring added
            check[length][length] = true;
            for (int i = 0; i < length - 1; i++)
            {
                if (check[i + 1][length - 1]    // if from i + 1 to length - 1 is palindrome
                && 
                str[i] == command)  // and str[i] == command
                {
                    ans++;
                    // new palindromic substring exists
                    check[i][length] = true;
                    // mark as true;
                }
            }
            if (str[length - 1] == command)
            // if end == command -> another substring exists
            {
                ans++;
                check[length - 1][length] = true;
            }
            str += command;
            length++;
        }
        else
        {
            command = str[length - 1];
            // str.erase(str.length() - 1);
            str.pop_back(); ans--;
            // at lease a palindromic substr loses
            check[length - 1][length - 1] = false;
            // mark as nonexistent 
            for (int i = 0; i < length - 1; i++)
            {
                if (check[i][length - 1])
                {
                    ans--;
                    // if a substr contains, mark as no longer exist
                    check[i][length - 1] = false;
                }
            }
            if (str[length - 1] == command)
            {
                ans--;
                check[length - 2][length - 1] = false;
            }
            length--;
        }
        cout << ans << " ";
    }
    return 0;
}