Calculate the Number of Days Between Two Dates — CodeForge CodeForge — Programming Reference Subtracting two calendar dates looks like simple arithmetic until leap years, time zones, and daylight saving transitions all quietly disagree about how long a day actually is. Difficulty: Beginner–Intermediate Languages: Python · Java · JavaScript Read: ~9 min In this article…
Find the Number of Minutes in a HH:MM:SS Time String — CodeForge CodeForge — Programming Reference Splitting a duration string into its parts and turning it back into a single number — and the rounding decision that quietly changes what “number of minutes” even means. Difficulty: Beginner Languages: Python · JavaScript · Java Read: ~8…
Append a String to a File — CodeForge CodeForge — Programming Reference Append a String to a File Adding text to the end of a file without disturbing what’s already there — the open mode that matters, and why concurrent appends need more care than they look like they do. Difficulty: Beginner Languages: Python ·…
Append a String to a File — CodeForge CodeForge — Programming Reference Append a String to a File Adding text to the end of a file without disturbing what’s already there — the open mode that matters, and why concurrent appends need more care than they look like they do. Difficulty: Beginner Languages: Python ·…
Determine the Size of a File — CodeForge CodeForge — Programming Reference Determine the Size of a File A question that looks trivial until symbolic links, sparse files, and streamed sources show up — three ways to ask “how big is this,” and what each answer actually means. Difficulty: Beginner Languages: Python · Java ·…
I/O With Timeout — CodeForge CodeForge — Programming Reference I/O With Timeout Reading from a socket or a file handle that might just never respond — and the patterns that stop a hung connection from hanging your entire program. Difficulty: Intermediate Languages: Python · C · Java Read: ~10 min In this article Why blocking…
Merge Sort — CodeForge CodeForge — Programming Reference Merge Sort Split until trivial, merge back in order — the divide-and-conquer sort with a guaranteed O(n log n) ceiling and no nasty worst case hiding underneath it. Difficulty: Intermediate Languages: Python · Java · OCaml Read: ~10 min In this article The core idea: divide, sort…
Bubble Sort — CodeCodex Sort Algorithms Bubble Sort The slowest sort most programmers learn first — and exactly because of that, the clearest possible introduction to what “comparing and swapping” even means. Difficulty: Beginner Languages: Python · Java · C Read: ~9 min In this article The core idea: repeated neighbor swaps Why it’s called…
Quicksort — CodeCodex Sort Algorithms Quicksort The divide-and-conquer sort that’s fast on average, fragile in the worst case, and still the default choice behind most general-purpose sort functions in use today. Difficulty: Intermediate Languages: C · Python · Java Read: ~10 min In this article The core idea: partition, then conquer Choosing a pivot —…
Calculate a Triangle Number — CodeCodex Math The sum of the first n integers, the shape that gives it its name, and the one-line formula that replaces an entire loop. Difficulty: Beginner Languages: Python · JavaScript · Pascal Read: ~8 min In this article What a triangle number is, visually and numerically The loop-based approach…