Questions tagged [grid-deduction]

Puzzles such as Sudoku or Kakuro, where the final state of a pre-existing grid must be deduced logically through clues placed within and/or around the grid. For puzzles where you are given a list of clues which can be used to compose a grid to solve them logically, use the [logic-grid] tag instead.

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6
votes
1answer
258 views

Shingoki: Choices

This is a Shingoki puzzle. The goal is to make a single loop in the grid which satisfies the following rules.1 The line passes through dots and numbers in the grid, vertically and horizontally, ...
5
votes
3answers
804 views

Will you be the first to get free?

It is your first day in prison and you are approached by a guard having a hunch for puzzles. He tells you that he gives every new prisoner the chance to be freed if they can present him with a version ...
5
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2answers
716 views

Incomplete Word Rectangle

This is an incomplete word rectangle: When completed, every row will contain a common English word with four letters, and every column will contain a word with five letters. All of these are common ...
5
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4answers
1k views

Sum in a sudoku with sum total of 15 and 45

I have created a sudoku puzzle with the following restrictions: Each row and column sum to $45$. Each row and column in the nine $3$ by $3$ sub-grids sum to $15$. Is such a sudoku unique?...
5
votes
2answers
576 views

Multiplicative sudoku (don’t use computers please)

If I place all the numbers from 1 to 9 in a 3x3 grid and I add the products of each row and column, then what is the minimal and the maximal sum? For example, the sum is 450 on the picture above
5
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4answers
285 views

Fill the grid (pattern)

Can you guess what comes in place of the question mark? Here's a text-based version of the table: ...
5
votes
1answer
659 views

Heyawake - why is this wrong solution

Dear people, Why does this particular android game not accept the solution on the right side? Rules in the app:
5
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2answers
821 views

Special Sudoku, with windows pattern

Solve this Sudoku, with rules : Every blue square means, it is the left-top of a 3x3 block with each numbers [1 to 9] appearing only once there. There is only one unique solution. Check the example. ...
5
votes
4answers
483 views

Where to pitch the next tent?

I am stuck solving this "Trees and Tents" puzzle. How to solve the rest of the puzzle? For does who don't know the puzzle, these are the "Trees and Tents" rules: A tent must be placed next to every ...
5
votes
2answers
462 views

Simple grid deduction puzzle

I will let you figure the rules of this one yourselves. Here is the empty grid to assist solvers. Here is a text version of the grid: ...
5
votes
1answer
87 views

Follow the path of relation through the grid #6

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
5
votes
2answers
168 views

Follow the path of relation through the grid #5

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
5
votes
2answers
344 views

Another puzzle for who has long boring days

The rules: each row must have the digits from 0 to 9. The sum of the digits in the column is shown at the bottom of the column. The same number can appear more than once in a column. Adjacent boxes ...
5
votes
1answer
206 views

Spiral Stumper Series: Fillomino

Spiral Stumper Series is a $5$-puzzles series taken from the Final Round of a local (national) contest, KPK, which has been ended recently and authored by me. The theme is spiral and each puzzle is ...
5
votes
1answer
1k views

A new puzzle - Sudoku X V

If someone is able to find the solution... I found 2,3,8 on line 5, column 3-4-5, but after that I am blocked, it looks too difficult for me.
5
votes
2answers
299 views

Word Rectangle #2

As with my previous puzzle, this is an unfinished word rectangle: Can you fill in the blanks? When completed, every row will contain a common English word with five letters, and every column will ...
5
votes
3answers
278 views

Fill $N$ by $M$ grid with numbers in such a way that any given cells' neighbors are different

Create an $N$ by $M$ grid with numbers in such a way that satisfies following conditions: numbers should be integers that range from $1$ to $r$. for any cell $C$, all its adjacent neighbors (i.e. ...
5
votes
1answer
179 views

Sums to a square number

arrange the numbers 0 to 9 in the circles below, following these rules : Every row of 3 or 4 circles sums to a square number. Every diagonal of 3 circles sums to a square number. Every green circle ...
5
votes
1answer
1k views

Difference square logic (5x5)

Rules : Arrange numbers 1 to 25 to the squares, and each number only occurs once. Green squares are the difference from its left square and its right square. Green squares are also the difference ...
5
votes
1answer
182 views

A Nurikabe-Kakurasu study

This puzzle is another study for a (hopefully) upcoming puzzle, which I think has an interesting solution path. This puzzle contains a Nurikabe and a Kakurasu (see a previous puzzle for details). The ...
5
votes
2answers
166 views

Monday's Dominosa Problem

Dominosa or Domino Solitaire is a logic puzzle with a similar feel to Sudoku. Given a grid of numbers, you have to lay out the dominoes so they match the numbers, without duplicated or missing ...
5
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2answers
223 views

SafeCracker #2 - The Mission Continues

Thanks to an alert StackE user, we were able to get the first safe open. Mission Details This next safe is in a former employee's house. He is gone for now, so we have no time to spare. We weren't ...
5
votes
1answer
346 views

Modified Intersection Puzzle

This is a slightly modified version of the Intersection Puzzle introduced by user477343 here. In this case, you are given a $7 \times 8$ grid with circles and boxes provided in some of the cells. ...
5
votes
1answer
584 views

Stuck in 6x6 skyscraper puzzle

I don't know how to continue, can anyone tell me which next number am I able to add? Here is the puzzle (there are clues at edges), and below are possibilities. Feel free to tell me if I made mistake, ...
5
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2answers
269 views

Where did my uncle go?

That damned uncle of mine! Running out without telling us has become too commonplace in our house. I did manage to find these two nonograms and a note this time though. "Fear not nephew! I am ...
5
votes
1answer
199 views

Nurikolor (Level 2)

Previous level: Nurikolor (Level 1) Next level: Nurikolor (Level 3) Level 2 of Nurikolor is now here. As a recap, here are the rules, but changed "X" to colors. There are colored numbers on ...
5
votes
1answer
181 views

Quick Moon-or-Sun Puzzles: 2x1-Dominoes and 1x1-Checkerboards

Moon-or-Sun (adapted from Nikoli) Draw a line to make a single loop. Lines pass through the centers of cells, horizontally, vertically, or turning. The loop never crosses itself, branches ...
5
votes
1answer
154 views

Masyu turned vanilla

Tried to make something clever, but it didn't work out so you're getting a vanilla masyu instead. Normal masyu rules apply.
5
votes
2answers
481 views

Sto-stone puzzle

Sto-stone is a puzzle made by Nikoli. Here are the rules: You must color the cells with black with the following rules: There are rooms enclosed in bold lines. The number on the room shows the ...
5
votes
3answers
462 views

Haisu: MathGrant

HAISU is a portmanteau of three Japanese words - 'hairu', to enter, 'su', number, and 'hausu', an English borrow word meaning house, of course. Together, we get a meaning of 'enter number house', ...
5
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1answer
189 views

Just Another Sudoku for PSE

Crafted with love for PSE, <3
5
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1answer
199 views

Triple (Almost) Gaps - Schezo's Edition

Today (Mar 16) is Schezo's birthday! Happy birthday my little creeper boi~ <3 Clarifications: $C$ may or may not be equal to $1$. The set actually tells you that at least one of $\{C,M,N,P,R,T\}$ ...
5
votes
1answer
325 views

Haisu: Pink Rose

HAISU is a portmanteau of three Japanese words - 'hairu', to enter, 'su', number, and 'hausu', an English borrow word meaning house, of course. Together, we get a meaning of 'enter number house', ...
5
votes
1answer
161 views

All That Remains Sudoku

. 2 . | . 7 . | . . 9 . 9 8 | . . . | . . . 3 . . | 9 . . | . . . ---------+---------+-------- 2 . 7 | . . . | . . . . 1 5 | 7 . . | . . . . . . | 1 5 8 | . ...
5
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1answer
217 views

Square Spin #3: Hickory Dickory Dock

Square Spin History: #1>#2>#3 Recap of the Rules Basic rules from #1 Ambiguity, Un and Re squares from #2 Problem #3: Hickory Dickory Dock The mouse ran up the clock. ...but ...
4
votes
4answers
714 views

Flow Free Favourites

Recently, I have been amusing myself with the interesting puzzles provided by the excellent Flow Free puzzle app. Since I couldn't find a way to bookmark my favourite puzzles, I took up a habit of ...
4
votes
2answers
198 views

Bullet Drop™ #1

Concept Here is a basic example grid: AB 1\/ 2\/ ×× The player must first modify the grid by switching the slashes \ and <...
4
votes
1answer
165 views

Damaged 4x4 grid

John had a great party yesterday ; but he had a very important piece of paper in his pocket, and an unidentified liquid damaged it. One third of the information is lost. It looks like this now : The ...
4
votes
2answers
239 views

How to solve the puzzle below?

Someone send me a puzzle in Discord and the creator said you can ask other people to help me solve. Here is one of the problems I can't solve. Could anyone help me? It is hard!
4
votes
1answer
330 views

Can someone, please, help me to solve this level of the game „Flow Mania”?

It's very hard for me to solve this level. I just can't figure it out! Rules: Draw a lines to connect like-colored dots. A complete solution will utilize every empty square in the grid.
4
votes
2answers
328 views

Find the ? in this grid

Find question mark in this grid with numbers. csv version: 9,6,7,3 2,4,7,6 4,1,5,8 3,0,3,? Hint: You use all numbers to find ? and it is much more simple ...
4
votes
2answers
209 views

Modified Futoshiki

This is a modified Futoshiki Place the numbers 1 to 5 such that each row, and column contains each of the digits 1 to 5. Squares with same color, contains each of the digits 1 to 5 too.
4
votes
1answer
114 views

Finding the Missing Word in a Crossword

On each of the 25 cells of this board, place one of the letters A, C, M or S so that, in alphabetical order, nine of the ten words that can be read down or across are the following: AACAC AMCAS ...
4
votes
1answer
155 views

Hamiltonian Puzzle Algorithm

I know how to create a Hamiltonian path or circuit for a given grid size (in which all nodes are free). However I just wonder how to create specific type of puzzles like the ones given below. I'm ...
4
votes
1answer
164 views

The revenge of 3D light bulbs

This is a three-dimensional Akari puzzle (also known as Light Up). The five squares represent the layers of a $5\times5\times5$ cube, top to bottom. The objective is to add light bulbs into any number ...
4
votes
1answer
1k views

Can you solve this kakuro puzzle?

This kakuro puzzle comes from the newest edition of Topple, an indie puzzle magazine I run. For those who are unfamiliar with kakuro, here are some instructions: Kakuro consists of a blank grid with ...
4
votes
2answers
565 views

36-length snake in a 6x6 grid

Based on https://brilliant.org/weekly-problems/2017-05-29/advanced/?p=4 We need to fill a 6x6 grid using the numbers 1-36, each cell having a single unique number, such that: Every two consecutive ...
4
votes
1answer
62 views

Jewel Cave: Long Reach

As in a previous puzzle, the goal of this Jewel Cave is to place the given shapes (in this case, the standard pentomino set) into the grid, subject to the following rules: All unshaded squares must ...
4
votes
1answer
142 views

Follow the path of relation through the grid #7

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
4
votes
2answers
243 views