PUZZLE TECHNIQUES

SKYSCRAPER SUDOKU

Below we will explain techniques for solving a Skyscraper Sudoku. You can go to our page Skyscraper Sudoku and solve this puzzle online.

HOW TO SOLVE SKYSCRAPER SUDOKU

• Look for clues 1. Now only the highest skyscraper is visible.
• Look for clues 9. Now you can see all the skyscrapers.
• Try to place the highest skyscrapers first.
• Don't forget the normal sudoku rules and techniques.

SKYSCRAPER SUDOKU RULES

A Skyscraper is a sudoku with clues along its sides. In this variant, the numbers symbolize skyscrapers. Number 1 is the smallest skyscraper and number 9 is the largest. In each row and column the number of visible skyscrapers, as viewed from the direction of each clue, is equal to the value of the clue. So higher skyscrapers block the view of lower skyscrapers.

SKYSCRAPER SUDOKU TECHNIQUES

CLUES OF 1

Examine your skyscraper puzzle and look for 1 clues. This means that only the highest skyscraper in the row or column is visible. Therefore in the example below, the highest skyscraper with 9 floors must be placed next to the clue 1 to block the view of the remaining buildings.

CLUES OF 9

Try to find clues of 9. This means that all skyscrapers are visible when viewing the row or column from the direction of the clue 9. Therefore the 9 numbers must be placed in ascending order from 1 to 9 so that the view of no number gets blocked.

HIGH NUMBERS

The next step after looking for clues 1 and 9 is trying to place the highest skyscrapers. In our example we have clue 6 in column 7. We discuss all the numbers that we can place. Because of number 8 in R5C7 all the numbers must be in ascending order.

• R1C7: number 3 is the only possibility
• R2C7: number 4 is the only possibility
• R4C7: number 7 is the only possibility because number 6 is already in subgrid 6
• R6C7: number 2 is the only possibility because number 6 is already in subgrid 6
• R8C7: number 9 is the only possibility because of clue 2
• R9C7: number 6 is the only possibility