Leetcode claims that exception is not handled which I handled-CodePudding

I am trying to solve Dynamic Programming questions from leetcode. Started from the easiest ones. Fibonacci. I handled the IndexOutOfRangeException and tried my code with different values on my computer. But when I submit it, leetcode says:

Runtime Error
Unhandled exception. System.IndexOutOfRangeException: Index was outside the bounds of the array.
At Solution.Fib(Int32 n)
At __Driver__.Main(String[] args)

Here is the code:

public class Solution
{
    public int Fib(int n)
    {
        int[] table = new int[n   1];

        // Seed the trivial answer.
        table[1] = 1;

        // Iterate and fill further positions based on current values.
        for (int i = 0; i < n; i  )
        {
            try
            {
                table[i   2] = table[i]   table[i   1];
            }
            catch (IndexOutOfRangeException ex)
            {
                // Out of array bounds.
            }
        }

        return table[n];
    }
}

CodePudding user response：

Your return could be triggering that because it is outside the try/catch. Based on your logic, I don't see how you would actually get IndexOutOfRangeException there, but it could be a code quality scanner that isn't happy. Another possibility is that because your logic will always get IndexOutOfRangeException within the try/catch, the system is upset because you didn't actually 'handle' the catch, just ignored it.

CodePudding user response：

Thanks to the people at the comments, I noticed I forgot handle the cases with n<1.

public class Solution
{
    public int Fib(int n)
    {
        if (n < 1)
        {
            return 0;
        }

        int[] table = new int[n   1];

        // Seed the trivial answer.
        table[1] = 1;

        // Iterate and fill further positions based on current values.
        for (int i = 0; i < n; i  )
        {
            try
            {
                table[i   2] = table[i]   table[i   1];
            }
            catch (IndexOutOfRangeException ex)
            {
                // Out of array bounds.
            }
        }

        return table[n];
    }
}

Thanks to the Klaus from the comments n - 1 instead of n will also avoid the IndexOutOfRangeException exception so I don't have to use try catch anymore.

for (int i = 0; i < n - 1; i  ){
    table[i   2] = table[i]   table[i   1];
}