From 8947bdd61ce76ba0b3857c404f162855393255fe Mon Sep 17 00:00:00 2001 From: newt Date: Wed, 9 Oct 2024 18:10:10 +0100 Subject: [PATCH] feat(problem): 11 - largest product in a grid --- readme.md | 4 +- src/bin/11.rs | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++ src/main.rs | 2 +- 3 files changed, 111 insertions(+), 3 deletions(-) create mode 100644 src/bin/11.rs diff --git a/readme.md b/readme.md index d9b509d..d7e2e26 100644 --- a/readme.md +++ b/readme.md @@ -9,7 +9,7 @@ All of the solutions here are written in rust. [main.rs](src/main.rs) is the hom ## Challenge Completion -### 10 out of 100 public challenges completed. +### 11 out of 100 public challenges completed. - [x] 1 - [Multiples of 3 or 5](src/bin/1.rs) - [x] 2 - [Even Fibonacci numbers](src/bin/2.rs) @@ -21,7 +21,7 @@ All of the solutions here are written in rust. [main.rs](src/main.rs) is the hom - [x] 8 - [Largest product in a series](src/bin/8.rs) - [x] 9 - [Special Pythagorean triplet](src/bin/9.rs) - [x] 10 - [Summation of primes](src/bin/10.rs) -- [ ] 11 - Largest product in a grid +- [x] 11 - [Largest product in a grid](src/bin/11.rs) - [ ] 12 - Highly divisible triangular number - [ ] 13 - Large sum - [ ] 14 - Longest Collatz sequence diff --git a/src/bin/11.rs b/src/bin/11.rs new file mode 100644 index 0000000..dd89d9d --- /dev/null +++ b/src/bin/11.rs @@ -0,0 +1,108 @@ +/* +Problem 11 - Largest product in a grid + +In the 20×20 grid below, four numbers along a diagonal line have been marked in red. +08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08 +49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00 +81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65 +52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91 +22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80 +24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50 +32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70 +67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21 +24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72 +21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95 +78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92 +16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57 +86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58 +19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40 +04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66 +88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69 +04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36 +20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16 +20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54 +01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48 +The product of these numbers is 26 × 63 × 78 × 14 = 1788696. +What is the greatest product of four adjacent numbers in the same direction (up, down, left, right, or diagonally) in the 20×20 grid? +*/ + +fn largest_grid_product(grid: Vec>, adjacent_digits: usize) -> usize { + let mut products: Vec = vec![]; + + for (i, row) in grid.iter().enumerate() { + for (j, _) in row.iter().enumerate() { + let horizontal = j < row.len() - adjacent_digits + 1; + let vertical = i < grid.len() - adjacent_digits + 1; + + // Horizontal product + if horizontal { + let selection = &row[j..(j + adjacent_digits)]; + products.push(selection.iter().product()); + } + + // Vertical product + if vertical { + let mut selection: Vec = vec![]; + + for k in 0..adjacent_digits { + selection.push(grid[i + k][j]); + } + + products.push(selection.iter().product()); + } + + // Forward diagonal product + if vertical && horizontal { + let mut selection: Vec = vec![]; + + for k in 0..adjacent_digits { + selection.push(grid[i + k][j + k]); + } + + products.push(selection.iter().product()); + } + + // Reverse diagonal product + if vertical && j > adjacent_digits - 2 { + let mut selection: Vec = vec![]; + + for k in 0..adjacent_digits { + selection.push(grid[i + k][j - k]); + } + + products.push(selection.iter().product()); + } + } + } + + return *products.iter().max().unwrap(); +} + +fn main() { + let grid: Vec> = vec![ + vec![8, 2, 22, 97, 38, 15, 0, 40, 0, 75, 4, 5, 7, 78, 52, 12, 50, 77, 91, 8], + vec![49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 4, 56, 62, 0], + vec![81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 3, 49, 13, 36, 65], + vec![52, 70, 95, 23, 4, 60, 11, 42, 69, 24, 68, 56, 1, 32, 56, 71, 37, 2, 36, 91], + vec![22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80], + vec![24, 47, 32, 60, 99, 3, 45, 2, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50], + vec![32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70], + vec![67, 26, 20, 68, 2, 62, 12, 20, 95, 63, 94, 39, 63, 8, 40, 91, 66, 49, 94, 21], + vec![24, 55, 58, 5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72], + vec![21, 36, 23, 9, 75, 0, 76, 44, 20, 45, 35, 14, 0, 61, 33, 97, 34, 31, 33, 95], + vec![78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 3, 80, 4, 62, 16, 14, 9, 53, 56, 92], + vec![16, 39, 5, 42, 96, 35, 31, 47, 55, 58, 88, 24, 0, 17, 54, 24, 36, 29, 85, 57], + vec![86, 56, 0, 48, 35, 71, 89, 7, 5, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58], + vec![19, 80, 81, 68, 5, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 4, 89, 55, 40], + vec![4, 52, 8, 83, 97, 35, 99, 16, 7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66], + vec![88, 36, 68, 87, 57, 62, 20, 72, 3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69], + vec![4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 8, 46, 29, 32, 40, 62, 76, 36], + vec![20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 4, 36, 16], + vec![20, 73, 35, 29, 78, 31, 90, 1, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 5, 54], + vec![1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48] + ]; + + let value = largest_grid_product(grid, 4); + + println!("The largest product formed by four digits in the same direction in the given grid is {value}"); +} diff --git a/src/main.rs b/src/main.rs index 45335dd..c7d516d 100644 --- a/src/main.rs +++ b/src/main.rs @@ -166,7 +166,7 @@ fn main() {{ drop(readme_file); // Announce completion! - println!("{}", "File successfully created! Good luck (:".green()); + println!("{}", "File successfully created! Good luck (:".green().bold()); Ok(()) }