When performing a region search on a PR quadtree, we need only search those subtrees of an internal node whose corresponding square falls within the query circle. This is most easily computed by comparing the x and y ranges of the query circle against the x and y ranges of the square corresponding to the subtree. However, as illustrated by Figure 13.13, the x and y ranges might overlap without the circle actually intersecting the square. Write a function that accurately determines if a circle and a square intersect.
