Optimally Packing a Large Square by Unit Squares
Rory McClenagan
TL;DR
The paper tackles the classical square packing problem by unit squares, establishing an improved bound $W(x)=O(x^{3/5})$ on the wasted area for a square of side length $x$. It introduces a two-stage geometric packing strategy: first packing most of $S(x)$ with inclined stacks to form a trapezoidal region $T$, then applying two complementary packing algorithms within $T$ to control angular drift and error accumulation. Key insights include deriving angular relations, such as $\\theta \\asymp 1/\\sqrt{h}$ and $\\varphi^2 \\asymp 2\\theta$, and balancing parameters so that the total wasted area scales as $W(x)=O(x^{3/5})$ when $h\\sim x^{4/5}$. By carefully coordinating the two algorithms and optimizing $h$, the authors achieve the claimed bound and refine prior results in unit-square packing. This has implications for combinatorial geometry and may inform related packing and tiling problems with sharp asymptotics.
Abstract
We show that a large square of sidelength $x$ can be packed by unit squares in a manner so that the wasted space $W(x) = O(x^{3/5})$.
