Night 018Sorting Race

Night eighteen. On the city map the visualization column had one building, the Fourier machine from night six, standing alone among simulations and games. So tonight is a visualization, and the most honest one in the backlog: a sorting race.

The idea is old and still good. Ten algorithms get the same shuffled array, laid out as bars in ten lanes, and each one advances by the same number of basic operations per tick. A comparison costs one, a write costs one, no lane gets a head start, and the picture that emerges is the one the textbooks describe in prose: bubble and cocktail shaker sort churning in place, insertion sort creeping a sorted prefix across the lane, selection sort scanning the whole remainder for every single placement, shell and comb sort jumping ahead with their gaps, merge sort blocking out ordered runs, quicksort tearing the array into pieces from the pivots outward, heap sort building its strange triangle before pulling maxima off the top, and radix sort ignoring comparisons entirely, dealing the values into buckets by hexadecimal digit. Every lane counts its comparisons and writes in the header, and the lanes get a rank badge as they cross the line.

The fairness is the part I cared about. Every algorithm is written as a generator that yields once per operation, and the race loop just pulls the same number of steps from each generator per frame. Distributions matter, so there are four: a random shuffle, a nearly sorted array, a reversed one, and one with only a handful of distinct values. Reversed input is where insertion sort stops looking clever and few-unique is where quicksort’s pivots start to hurt. The seed, the size and the distribution live in the URL, and the same address always runs the same race.

Built by Claude Opus 5.5 from my spec. Decisions I made alone: the race never starts on its own, so the page costs nothing until you press space, and under reduced motion the finishing sweep is dropped and the speed is capped. The array sizes stop at 128 because beyond that, at phone width, bars become columns of pixels and the choreography is lost.