Hi I've been doing Project Euler problems lately but I'm having trouble with Problem 18, here it is:

By starting at the top of the triangle below and moving to adjacent numbers on the row below, the maximum total from top to bottom is 23.

3

7 4

2 4 6

8 5 9 3

That is, 3 + 7 + 4 + 9 = 23.

Find the maximum total from top to bottom of the triangle below:

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

NOTE: As there are only 16384 routes, it is possible to solve this problem by trying every route. However, Problem 67, is the same challenge with a triangle containing one-hundred rows; it cannot be solved by brute force, and requires a clever method! ;o)

My algorithm for finding the max total is correct. I tested it by manually entering the numbers in a 2d array and the program ran fine. The reason I don't want to do it that way is as this Problem says Problem 67 is the same except much larger numbers and I don't want to be typing numbers all day and also I want to practice manipulating files etc.

Anyway to the point I suppose the best thing I can do really is show you my code and the errors I'm getting. I did some debugging but I can't seem to figure out why the problem is occurring. When I run the program it gives an ArrayIndexOutOfBoundsException(). The .txt file consists of the large group of numbers in the problem description above.

The errors then are:Code:public class Problem18 { public static void main(String[] args) throws Exception { Problem18 p18 = new Problem18() ; p18.maxTotalPath() ; } public int[][] readFile() throws Exception { ClassLoader loader = Thread.currentThread().getContextClassLoader() ; InputStream file = loader.getResourceAsStream("Triangle.txt") ; Scanner scan = new Scanner(file) ; int[][] triangle = new int[15][15] ; int m = 0, n = 0 ; String line ; while(scan.hasNext()) { line = scan.nextLine() ; String[] numbers = line.split(" ") ; for(int i = 0 ; i < numbers.length ; i++) { triangle[m][n] = Integer.parseInt(numbers[i]) ; //System.out.print(triangle[m][n] + " ") ; n += 1 ; } n = 0 ; // System.out.println("") ; m += 1 ; } scan.close() ; return triangle ; } public void maxTotalPath() throws Exception { int[][] arr = readFile() ; for (int i = arr.length - 2 ; i >= 0 ; i--) { for (int j = 0 ; j < arr[i].length; j++) { arr[i][j] += Math.max(arr[i + 1][j], arr[i + 1][j + 1]); } } System.out.println(Integer.toString(arr[0][0])) ; } }

Any help would be much appreciated thanks!Code:Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 15 at com.jconnolly.projeuler.problems.Problem18.maxTotalPath(Problem18.java:83) at com.jconnolly.projeuler.problems.Problem18.main(Problem18.java:44)