I had a phone interview, then an on-site invitation consisting of four 45-minute interviews, back-to-back, with no breaks.

After the committee's deliberation, I was accepted. A manager contacted me and I received an offer.

Imagine a matrix of positive integers. You need to walk from the top-left element to the bottom-right element. You can only walk to the up, bottom, left, or right neighbor elements. You can only walk to a neighboring element that is less than or equal to the current element (like water flow).

Return whether such a path can be found.