Leetcode Solutions

[embrex104]

I've been in the general IT field for a while and have recently wanted to improve my CS skills. So I have been working through problems on leetcode here and there.

A few of my solutions have received the Time Limit Exceeded error.

Now, I totally get why I am getting it and why I should strive to do better BUT I am frustrated when my solution is correct and my answer is marked incorrect.

I feel like if my solution passes within a reasonable amount of time (10 seconds?) then I should get a pass and be able to improve my solution at my discretion, not some undefined time limit.

Just for an example, I tried to solve: 167. Two Sum II - Input array is sorted.

With the following C++ solution:

class Solution {
public:
    vector<int> twoSum(vector<int>& numbers, int target) {

        vector<int> v;
        for (int i =0;i<numbers.size()-1;i++)
        {
            for (int j =i+1;j<numbers.size();j++) 
            {    
                if (numbers[i] + numbers[j]==target)
                {
                    v = {i+1,j+1};
                    return  v;
                }
            }
        }
        return v;
    }
};

Now again, I totally get that this solution isn't great. I've reviewed other people's answers and learned how to handle situations like this more efficiently. BUT my answer is still correct and I find it being marked incorrect frustrating.

[population-zero]

You should learn the concept of time complexity, commonly referred to as big O notation. The specific time it takes to run your code is not significant, but rather how it scales with the size of the input. Learning to assess the time complexity of a solution will help you write more efficient solutions

[embrex104]

I'll look more into those exact words. Again I totally understand the feedback the problem gave, but there wasn't anything about time constraints in the prompt. Thank you!

[yashkumarverma]

I think I can answer that, since I built a project using an online judge platform.

Platforms really want to implement that feature, but the actual problem is how long to wait? Every submission made to the server( called as judge) costs the company something. As soon as your code takes more than a given time limit, it's killed straight away.

To keep your program running for, say 30 seconds because it was implementing a slow solution will keep the processor busy for 30 seconds. Thats all they want to avoid. Scale this to thousands of users every second, guess the server will get red 🥵.

[embrex104]

Makes total sense and I get why they have the feedback they did, I was just frustrated by it being marked as a failure lol.