corrected

Description updated, more and random tests added.

i did this as well (using sum of consecutive integers)! Only I didn't use max(arr) as the length of arr was already one of the #s needed in the calculation!

My python solution still has rounding problem. Some people stated that problem is resolved but it does not work for me.

need test case

This question is vague. I am not sure what kind of skill it will potencially adds.