HAPPYNURI wins the Nurikabe Tournament

Abstract

0Table 1: The participants and final standings. The game Nurikabe is a kind of pencil puzzle introduced by Nikoli Inc. (1991), a Japanese puzzle magazine publisher. The game Nurikabe is played on a typically rectangular grid of cells that consists of one black and several white islands, each of which is a group of connected cells. In a Nurikabe puzzle, some cells initially contain numbers as shown in Figure 1(a), each of which indicates the size of the white island that contains the cell only and does not contain any other cells with numbers. These white islands are separated by one black island of which the cells cannot form a 2 x 2 square. Figure 1(a) shows one example of Nurikabe puzzle and Figure 1(b) shows its solution. Nurikabe has been shown to be NP-complete by McPhail (2003) and Holzer et al. (2004).