Most uptime tools answer the same question. They tell you "is service X up?" from one vantage point — the monitoring server. But in a hybrid cloud, "up" is not a property of a service. It's a property of a path.
A single-server monitor (Uptime Kuma, Pingdom...
Given the root of a binary tree, return its preorder traversal.
The challenge is to perform the traversal:
Without Recursion
Without Stack
O(1) Extra Space
In an interview, you can expl...
Every "free proxy list" you find is the same story: a giant wall of ip:port lines, 90% of them already dead, no idea which are HTTP or SOCKS, no idea where they exit. You paste 500 into your scraper and three of them work.
So I put up a small one that's actually checked: gproxy...
I spent 12 years on the Amazon inbound dock. Every box, every case, every unit — scanned. Over those years, I saw every barcode failure mode that exists. Here is what actually matters.
Every barcode format requires empty white space on both sides. EAN-13 needs 11x the narrowest bar width. ITF-14 adds a thick bearer bar because corruga...
Given the root of a binary tree, return the nodes visible when the tree is viewed from the top.
For every horizontal distance (HD), only the first node encountered should be included.
In an interview, you can explain it like this:
Compute the horizontal distan...