You could've figured out this one with basic familiarity with how graphs are represented, constructed, and navigated, and just working through it.
One way to often arrive at it is to just draw some graphs, on paper/whiteboard, and manually step through examples, pointing with your finger/pen, drawing changes, and sometimes drawing a table. You'll get a better idea of what has to happen, and what the opportunities are.
This sounds "Then draw the rest of the owl," but it can work, once you get immersed.
Then code it up. And when you spot a clever opportunity, and find the right language to document your solution, it can sound like a brilliant insight that you could just pull out of the air, because you are so knowledgeable and smart in general. When you actually had to work through that specific problem, to the point you understood it, like Feynman would want you to.
I think Feynman would tell us to work through problems. And that Feynman would really f-ing hate Leetcode performance art interviews (like he was dismayed when he found students who'd rote-memorize the things to say). Don't let Leetcode asshattery make you think you're "not good at" algorithms.
I despise leetcode interviews. These days, with coding LLMs, I see them as even less relevant than they were before.
Yet, you ask someone "how do you build an efficient LFU" and get blank stares (I just LOVE the memcache solution of regions and probabilistic promotion/demotion).
One way to often arrive at it is to just draw some graphs, on paper/whiteboard, and manually step through examples, pointing with your finger/pen, drawing changes, and sometimes drawing a table. You'll get a better idea of what has to happen, and what the opportunities are.
This sounds "Then draw the rest of the owl," but it can work, once you get immersed.
Then code it up. And when you spot a clever opportunity, and find the right language to document your solution, it can sound like a brilliant insight that you could just pull out of the air, because you are so knowledgeable and smart in general. When you actually had to work through that specific problem, to the point you understood it, like Feynman would want you to.
I think Feynman would tell us to work through problems. And that Feynman would really f-ing hate Leetcode performance art interviews (like he was dismayed when he found students who'd rote-memorize the things to say). Don't let Leetcode asshattery make you think you're "not good at" algorithms.