{"id":435,"date":"2012-07-29T01:32:33","date_gmt":"2012-07-29T05:32:33","guid":{"rendered":"http:\/\/www.joshho.com\/blog\/?p=435"},"modified":"2012-09-07T16:17:41","modified_gmt":"2012-09-07T20:17:41","slug":"project-euler-problem-11","status":"publish","type":"post","link":"https:\/\/www.joshho.com\/blog\/2012\/07\/29\/project-euler-problem-11\/","title":{"rendered":"Project Euler &#8211; Problem 11"},"content":{"rendered":"<p>Problem 11: What is the greatest product of four adjacent numbers on the same straight line in the 20 by 20 grid?<br \/>\n<!--more--><br \/>\n<code><\/p>\n<pre lang=\"java\">\r\n\r\nclass runner\r\n{\r\n\tpublic static void main (String[] args) throws java.lang.Exception\r\n\t{\r\n\t\tint[][] arr = {{8, 2, 22, 97, 38, 15, 0, 40, 0, 75, 4, 5, 7, 78, 52, 12, 50, 77, 91, 8},\r\n\t\t\t\t{49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 4, 56, 62, 0},\r\n\t\t\t\t{81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 3, 49, 13, 36, 65},\r\n\t\t\t\t{52, 70, 95, 23, 4, 60, 11, 42, 69, 24, 68, 56, 1, 32, 56, 71, 37, 2, 36, 91},\r\n\t\t\t\t{22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80},\r\n\t\t\t\t{24, 47, 32, 60, 99, 3, 45, 2, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50},\r\n\t\t\t\t{32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70},\r\n\t\t\t\t{67, 26, 20, 68, 2, 62, 12, 20, 95, 63, 94, 39, 63, 8, 40, 91, 66, 49, 94, 21},\r\n\t\t\t\t{24, 55, 58, 5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72},\r\n\t\t\t\t{21, 36, 23, 9, 75, 0, 76, 44, 20, 45, 35, 14, 0, 61, 33, 97, 34, 31, 33, 95},\r\n\t\t\t\t{78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 3, 80, 4, 62, 16, 14, 9, 53, 56, 92},\r\n\t\t\t\t{16, 39, 5, 42, 96, 35, 31, 47, 55, 58, 88, 24, 0, 17, 54, 24, 36, 29, 85, 57},\r\n\t\t\t\t{86, 56, 0, 48, 35, 71, 89, 7, 5, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58},\r\n\t\t\t\t{19, 80, 81, 68, 5, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 4, 89, 55, 40},\r\n\t\t\t\t{4, 52, 8, 83, 97, 35, 99, 16, 7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66},\r\n\t\t\t\t{88, 36, 68, 87, 57, 62, 20, 72, 3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69},\r\n\t\t\t\t{4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 8, 46, 29, 32, 40, 62, 76, 36},\r\n\t\t\t\t{20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 4, 36, 16},\r\n\t\t\t\t{20, 73, 35, 29, 78, 31, 90, 1, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 5, 54},\r\n\t\t\t\t{1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48}};\r\n\t\tlong large = 0;int xx=0;int yy=0;String type = \"\";\r\n\t\t\/\/Check horizontals\r\n\t\tfor(int y=0;y<arr.length;y++){\r\n\t\t\tfor(int x=0;x<arr[y].length-4;x++){\r\n\t\t\t\tlong prod = 1;\r\n\t\t\t\tfor(int i=0;i<4;i++){\r\n\t\t\t\t\tprod *= arr[y][x+i];\r\n\t\t\t\t}\r\n\t\t\t\tif(prod>large){\r\n\t\t\t\t\tlarge = prod;\r\n\t\t\t\t\txx=x;yy=y;\r\n\t\t\t\t\ttype = \"hor\";\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t\t\/\/Check verticals\r\n\t\tfor(int y=0;y<arr.length-4;y++){\r\n\t\t\tfor(int x=0;x<arr[y].length;x++){\r\n\t\t\t\tlong prod = 1;\r\n\t\t\t\tfor(int i=0;i<4;i++){\r\n\t\t\t\t\tprod *= arr[y+i][x];\r\n\t\t\t\t}\r\n\t\t\t\tif(prod>large){\r\n\t\t\t\t\tlarge = prod;\r\n\t\t\t\t\txx=x;yy=y;\r\n\t\t\t\t\ttype = \"ver\";\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t\t\/\/Check diagonals LT - RB\r\n\t\tfor(int y=0;y<arr.length-4;y++){\r\n\t\t\tfor(int x=0;x<arr[y].length-4;x++){\r\n\t\t\t\tlong prod = 1;\r\n\t\t\t\tfor(int i=0;i<4;i++){\r\n\t\t\t\t\tprod *= arr[y+i][x+i];\r\n\t\t\t\t}\r\n\t\t\t\tif(prod>large){\r\n\t\t\t\t\tlarge = prod;\r\n\t\t\t\t\txx=x;yy=y;\r\n\t\t\t\t\ttype = \"diagonals LT - RB\";\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\r\n\t\t\r\n\t\t\/\/Check diagonals LB - RT\r\n\t\tfor(int y=arr.length-1;y>=3;y--){\r\n\t\t\tfor(int x=0;x<arr[y].length-4;x++){\r\n\t\t\t\tlong prod = 1;\r\n\t\t\t\tfor(int i=0;i<4;i++){\r\n\t\t\t\t\tprod *= arr[y-i][x+i];\r\n\t\t\t\t}\r\n\t\t\t\tif(prod>large){\r\n\t\t\t\t\tlarge = prod;\r\n\t\t\t\t\txx=x;yy=y;\r\n\t\t\t\t\ttype = \"diagonals LB - RT\";\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t\tSystem.out.println(large);\r\n\t\tSystem.out.println(xx+\" \"+yy+\" \"+type);\r\n\t}\r\n}\r\n<\/pre>\n<p><\/code><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Problem 11: What is the greatest product of four adjacent numbers on the same straight line in the 20 by 20 grid?<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[56],"tags":[],"_links":{"self":[{"href":"https:\/\/www.joshho.com\/blog\/wp-json\/wp\/v2\/posts\/435"}],"collection":[{"href":"https:\/\/www.joshho.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.joshho.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.joshho.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.joshho.com\/blog\/wp-json\/wp\/v2\/comments?post=435"}],"version-history":[{"count":0,"href":"https:\/\/www.joshho.com\/blog\/wp-json\/wp\/v2\/posts\/435\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.joshho.com\/blog\/wp-json\/wp\/v2\/media?parent=435"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.joshho.com\/blog\/wp-json\/wp\/v2\/categories?post=435"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.joshho.com\/blog\/wp-json\/wp\/v2\/tags?post=435"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}