Solving KenKen puzzles — by not playing

Abstract

AbstractSolving KenKen puzzles requires more than making sure that numbers are used only once in a row and column of a matrix. Unlike Sudoku puzzles that can use any symbol and have sub-matrices, KenKen puzzles require actual integers and have contiguous cells, called cages. And, unlike a sub-matrix that contains a unique collection of numbers or symbols, KenKen puzzles have cages that must contain natural numbers representing a total as a function of its assigned arithmetic operation. For example, consider a 4 X 4 KenKen puzzle having a cage containing three cells whose total is 11 as a function of simple addition. One possible set of three numbers would be: 4 + 3 + 4 = 11. The objective is to complete the grid using numbers ranging from 1 to N that satisfies both cage arithmetic and row/column uniqueness. Depending on the size of the N X N grid, the number (and size) of the cages, as well as the arithmetic operations used, a KenKen puzzle offers a formidable challenge for logic puzzle fans. However, rat...