Hard Puzzles Book - Akari, Futoshiki, Kakuro, Suguru - 200 Hard Puzzles

Akari Akari (Light Up) is played on a rectangular grid of white and black cells. The player places light bulbs in white cells such that no two bulbs shine on each other, until the entire grid is lit up. A bulb sends rays of light horizontally and vertically, illuminating its entire row and column unless its light is blocked by a black cell. A black cell may have a number on it from 0 to 4, indicating how many bulbs must be placed adjacent to its four sides; for example, a cell with a 4 must have four bulbs around it, one on each side, and a cell with a 0 cannot have a bulb next to any of its sides. An unnumbered black cell may have any number of light bulbs adjacent to it, or none. Bulbs placed diagonally adjacent to a numbered cell do not contribute to the bulb count. Futoshiki Place numbers of the given range in the grid 9x9 such that every row and column contains each number exactly once. Inequality constraints must be satisfied. The open end of the sign denotes the greater number. Kakuro Each puzzle consists of a blank grid with sum-clues in various places. The object is to fill all empty squares using numbers 1 to 9 so the sum of each horizontal block equals the clue on its left, and the sum of each vertical block equals the clue on its top. In addition, no number may be used in the same block more than once. Suguru Suguru, also known as Tectonics or Number Blocks, is a Japanese puzzle invented by Naoki Inaba. The goal is to fill a given rectangular grid with numbers, so that every designated area contains a sequence of non-repeating, consecutive numbers, starting from 1 and going up. Also, adjacent (touching) cells should not contain the same number, even diagonally.