Greed is good. And Dijkstra’s algorithm is greedy. Dijkstra’s algorithm not only calculates the shortest (lowest weight) path on a graph from source vertex S to destination V, but also calculates the shortest path from S to every other vertex. My implementation in Python doesn’t…
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I’ve been learning graphs and dynamic programming somewhat interleaved. Dynamic programming tends to help solve graph problems because: Every problem solvable by dynamic programming can be represented in a DAG. A couple of things I discovered in my experiments: Using a queue for graph…
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I put on my sorting hat and watched many, many videos on sorting. The videos covered: bubble sort selection sort insertion sort heap sort merge sort quicksort counting sort radix sort There are several more sorting algorithms I could have gone into, but I had to stop somewhere. I’d like to…
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Technically, I started reading in April, but look at that stack! I’m not spending too much time reading on a daily basis right now. I want to get past the learning phase, then once I’ve had enough exposure to the main requirements for a coding interview, I’ll spend half the day…
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Splay trees are very simple as far as structure. A splay tree a binary search tree, so each node has a key, maybe a left child, and maybe a right child. There’s no subtree height, ranking info, or anything else. It’s pretty simple. It’s the splay algorithm that gives the splay…
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I’ve been sitting at self-balancing binary and other k-ary trees for a while, and I should be moving on to sorting algorithms tomorrow. But I was really amazed by an example of B-Tree usage in quick data accesses, that minimizes disk accesses in a smart way. I wanted to share it. From…
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Thanks to Let’s Encrypt, everyone can enjoy the security of an SSL-protected domain. To be fair, there are still a few places where their automated system won’t work, like if you’re running your web server on an irregular port, like 8443, or perhaps running in a load balanced…
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I’ve been reading an old but great book, The Unix Programming Environment (1984), by Brian Kernighan (of K&R C fame) and Rob Pike. I think it’s no longer in print, because the price on Amazon for a new paperback is over $50. On Half.com you can find it for less than $10. The book…
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I can call it terrible, because I designed it. – me The Just Really Bad Page Last week I spent some time overhauling the pricing page on TalkToTheManager. We had put out a new pricing page with the advent of text message surveys, and after about 2 months I revisited the pricing page and,…
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I made a departure after studying binary search trees to visit priority queues and heaps. I had planned to do this one later, but it kept coming up in lectures. I really like heaps. They are space and operation efficient, easy to understand and code, and make sorting easy. What’s not to…
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