ZCO Matched Brackets

general
, ,
1 
#include <bits/stdc++.h>
using namespace std;

bool sortbysecdesc(const pair<int,int> &a,
                   const pair<int,int> &b)
{
        return a.second > b.second;
}

int main()
{
    int n;
    cin >> n;

    int seq[n];

    for(int i = 0; i < n; i++)
        cin >> seq[i];

    vector < pair <int,int> > depths;
    vector < pair <int,int> > symbols;

    int i = 0;
    int pos, j, c, s, d;
    while(i < n)
    {
        c = 0;
        s = 0;
        pos = i;
        while(seq[i] == 1)
        {
            c++;
            s++;
            i++;
        }
        d = c;
        j = i;
        while(c != 0)
        {
            if(seq[j] == 2)
            {
                s++;
                c--;
            }
            else
            {
                s++;
                c++;
            }
            j++;
        }
        depths.push_back(make_pair(pos+2, d));
        symbols.push_back(make_pair(pos+1, s));

        i = j;
    }

    sort(depths.begin(), depths.end(), sortbysecdesc);
    sort(symbols.begin(), symbols.end(), sortbysecdesc);

    cout << depths[0].second << " " << depths[0].first << " " << symbols[0].second << " " << symbols[0].first << "\n";

    return 0;
}

I have coded the above solution for ZCO12001 and it does work when I run it offline using an IDE and it also works in case of custom input on CodeChef but RUN returns SIGTSTP and on submitting I get WA for all the test cases. Please help. Where am I going wrong? I have tried it with multiple sample test cases (that I generated on my own) and it works on all of them but fails every time on Submitting.