Solved ProjectEuler/011: php, ruby

ProjectEuler/011/desc.yml

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+title: What is the greatest product of four adjacent numbers on the same straight line in the 20 by 20 grid?
+url: http://projecteuler.net/problem=11
+
+desc: |
+  In the 2020 grid below, four numbers along a diagonal line have been marked in red.
+  What is the greatest product of four adjacent numbers in any direction (up, down, left, right, or diagonally) in the 2020 grid?
+  (See file input)
+ 
+solution: |
+  Bruteforce (Unless someone found a smarter way)
+
+solutions:
+  solve.php:
+    desc: Expects the matrix as stdin
+    language: php
+  solve.rb:
+    desc: Expects the matrix as stdin
+    language: ruby

ProjectEuler/011/input

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+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

ProjectEuler/011/solve.php

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+<?php
+
+foreach(file('php://stdin') as $line) {
+	$matrix[] = explode(' ', $line);
+}
+$max = 0;
+//Left and right
+for ($y = 0; $y < 19; $y++) {
+	for ($x = 0; $x < 16; $x++) {
+		$cmp = $matrix[$y][$x] * $matrix[$y][$x + 1] * $matrix[$y][$x + 2] * $matrix[$y][$x + 3];
+		$max = ($cmp > $max) ? $cmp : $max;
+	}
+}
+
+//Vertical
+for($x = 0; $x < 19; $x++) {
+	for ($y = 0; $y < 16; $y++) {
+		$cmp = $matrix[$y][$x] * $matrix[$y + 1][$x] * $matrix[$y + 2][$x] * $matrix[$y + 3][$x];
+		$max = ($cmp > $max) ? $cmp : $max;
+	}
+}
+
+//Diagonally left->down
+for($x = 0; $x < 16; $x++) {
+	for ($y = 0; $y < 16; $y++) {
+		$cmp = $matrix[$y][$x] * $matrix[$y + 1][$x + 1] * $matrix[$y + 2][$x + 2] * $matrix[$y + 3][$x + 3];
+		$max = ($cmp > $max) ? $cmp : $max;
+	}
+}
+
+//Diagonally right->down
+for($x = 4; $x < 19; $x++) {
+	for ($y = 0; $y < 16; $y++) {
+		$cmp = $matrix[$y][$x] * $matrix[$y + 1][$x - 1] * $matrix[$y + 2][$x - 2] * $matrix[$y + 3][$x - 3];
+		$max = ($cmp > $max) ? $cmp : $max;
+	}
+}
+
+echo $max;

ProjectEuler/011/solve.rb

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+matrix = []
+linenum = 0
+ARGF.lines("\n") do |line|
+	matrix[linenum] = Array.new
+	line.split.each do |str|
+		matrix[linenum] << str.to_i
+	end
+	linenum += 1
+end
+
+max = 0
+max = 0;
+#Left and right
+(0..19).each do |y|
+	(0..16).each do |x|
+		cmp = matrix[y][x] * matrix[y][x + 1] * matrix[y][x + 2] * matrix[y][x + 3];
+		if (cmp > max)
+			max = cmp
+		end
+	end
+end
+
+#Vertical
+(0..16).each do |y|
+	(0..19).each do |x|
+		cmp = matrix[y][x] * matrix[y + 1][x] * matrix[y + 2][x] * matrix[y + 3][x];
+		if (cmp > max)
+			max = cmp
+		end
+	end
+end
+
+#Diagonally left->down
+(0..16).each do |y|
+	(0..16).each do |x|
+		cmp = matrix[y][x] * matrix[y + 1][x + 1] * matrix[y + 2][x + 2] * matrix[y + 3][x + 3];
+		if (cmp > max)
+			max = cmp
+		end
+	end
+end
+
+#Diagonally right->down
+(0..16).each do |y|
+	(3..19).each do |x|
+		cmp = matrix[y][x] * matrix[y + 1][x - 1] * matrix[y + 2][x - 2] * matrix[y + 3][x - 3];
+		if (cmp > max)
+			max = cmp
+		end
+	end
+end
+
+puts max