All challenges

Pack bounded axis-aligned rectangles into a bin to maximize profit.

Place many grid points while avoiding the four corners of every axis-aligned rectangle.

Choose a subset whose sum is as close as possible to a target.

Choose bounded quadratic witnesses that cover high-weight modular residue queries.

Write a compact Push-Pop program that halts after exactly the requested odd number of steps.

Install subtree retuners on a rooted tree to improve prime-residue observatory coverage.

Sort a permutation with prefix and suffix swaps while minimizing the number of operations.

Place reflected and rotated polyominoes in a rectangle while minimizing occupied area.

Sort a permutation by moving individual elements while minimizing the declared move cost.

Partition a permutation into four subsequences to maximize LIS and LDS structure.

Transform one valid parenthesis sequence into another using limited structural operations.

Draw an axis-aligned polygon that catches more mackerels than sardines.