The basic tests are compared against a fixed number, the random tests use a funcion on the same input arrays to get the result, so if you mutate the input the values returned by that function are wrong.

Post your code here and make sure you Mark it as spoiler.

Thanks, finally pass it. But why it can pass the basic test, but not the random test?

Don't mutate the input

"Testing for arr1: [3439, 6163, -7789, 811, 1104] arr2: [-6422, 5565, 5526, 6233, 4736]"

Expected: 35004, instead got: 19366

I pass the basic test, but literally failed all of the random test. That is one of the random test. Why is it expecting 35004 instead of 19366? 19366 should be the right answer right?