18

euler18.php

@@ -0,0 +1,42 @@
+<?php
+/*
+* Gnieark's anwser to euler problem 18
+* https://projecteuler.net/problem=18
+*/
+
+$triangleStr="75
+95 64
+17 47 82
+18 35 87 10
+20 04 82 47 65
+19 01 23 75 03 34
+88 02 77 73 07 63 67
+99 65 04 28 06 16 70 92
+41 41 26 56 83 40 80 70 33
+41 48 72 33 47 32 37 16 94 29
+53 71 44 65 25 43 91 52 97 51 14
+70 11 33 28 77 73 17 78 39 68 17 57
+91 71 52 38 17 14 91 43 58 50 27 29 48
+63 66 04 68 89 53 67 30 73 16 69 87 40 31
+04 62 98 27 23 09 70 98 73 93 38 53 60 04 23";
+
+$arr=explode("\n",$triangleStr);
+$triangle=array();
+foreach($arr as $line){
+    $triangle[]=explode(" ",$line);
+}
+
+//se placer sur l'avant derniere ligne.
+while(count($triangle)>1){
+    $i=count($triangle) -2;
+    for($cell=0; $cell < count($triangle[$i]); $cell++){
+        if($triangle[$i +1 ][$cell] > $triangle[$i +1 ][$cell + 1]){
+            $triangle[$i][$cell] = $triangle[$i][$cell] + $triangle[$i +1 ][$cell];
+        }else{
+            $triangle[$i][$cell] = $triangle[$i][$cell] + $triangle[$i +1 ][$cell +1];
+        }
+    }
+    //remove last line
+    unset($triangle[$i+1]);
+}
+echo $triangle[0][0];