Thread: Problem with Project Euler problem 18

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
this is my code but it gives 21 instead of 23 what is wrong in the code thanks

    public static void main(String[] args) {
                List<List<Integer>> twoDim = new ArrayList<List<Integer>>();
                int  tempSum;
                int temp ;
 
        String[] inputLines = {"3","7 4","2 4 6","8 5 9 3"};
 
        for (String line : inputLines) {
            List<Integer> row = new ArrayList<Integer>();
 
            Scanner s = new Scanner(line);
            while (s.hasNextInt())
                row.add(s.nextInt());
 
            twoDim.add(row);
        }
        int lines = twoDim.size();
 
for (int i = lines-2 ; i >= 0; i--) {
   for (int j = 0; j <= i; j++) 
    {
 
       twoDim.get(i).add(j,twoDim.get(i).get(j)+Math.max(twoDim.get(i+1).get(j),twoDim.get(i+1).get(j+1)));
 
 
 
    }
}
System.out.println(twoDim.get(0).get(0));
    }

While your approach may be clever - then again, maybe TOO clever - it is not easy to understand or troubleshoot. I suggest you simplify the part of your program that chooses which value of the next row to add to the total so that you can add test lines to see what is going wrong. Think about how you'd do it in your head or with pencil and paper and code that.