How to debug on Codechef's IDE

help
1

Hello folks,

I’m new to codechef and just yesterday I tried to submit my solution in the practice segment. After initial hastles with NZEC, I submitted the program. However, now it tells me that the Time Limit has exceeded. Is there any way to know what input caused that? I tired a couple of Boundary conditions in my local IDE (IntelliJ) and it works fine and executes before timelimit. I wonder if a specific(unhandled) input is causing the issue. Is there anyway to know what Test scenarios are fed to program once it’s submitted and what are the results of these tests?

2

No, the testcases are (deliberately) kept secret. You’ll have to employ some ingenuity, observation and insight to try and work out why your program is timing out :slight_smile:

3

Try optimizing your approach. TLE is avoidable with careful optimization of your code.

4

Assuming the problem you’re trying to solve is ISHVALA, here’s something to start you off :slight_smile: Hopefully I haven’t made any mistakes with reading the question …

Try this testcase (3.8MB).

It was generated via this program, which I designed to a) fit the given constraints of the problem and b) hit your program with a case that will cause it to timeout :slight_smile:

#include <iostream>
#include <vector>

using namespace std;

int main()
{
    const int T = 100;
    cout << T << endl;
    for (int t = 0; t < T; t++)
    {
        const int N = 10'000;
        const int M = 10'000;
        cout << N << " " << M << endl;

        const int S = 2;

        auto generateRivers = [S](const int maxPos)
        {
            vector<int> riverPositions;
            int riverPos = 1;
            while (riverPos < maxPos)
            {
                riverPos = riverPos + S + (rand() % 2);
                if (riverPos <= maxPos)
                    riverPositions.push_back(riverPos);
            }
            return riverPositions;
        };

        const vector<int> horizontalRivers = generateRivers(N);
        const vector<int> verticalRivers = generateRivers(M);

        auto printRivers = [](const vector<int> riverPositions)
        {
            for (int i = 0; i < riverPositions.size(); i++)
            {
                cout << riverPositions[i];
                if (i != riverPositions.size() - 1)
                    cout << " ";
            }
            cout << endl;
        };

        cout << horizontalRivers.size() << " " << verticalRivers.size() << " " << S << endl;
        printRivers(horizontalRivers);
        printRivers(verticalRivers);

    }
}

For reference, the Problem Setter’s C++ solution takes 0.21 seconds to process this testcase. The time limit for C++ for this problem is 0.5 seconds, so I think the Java one is about twice that(?)

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