title: Largest product in a grid
body: <p>I'm stuck with this problem. I do think I've got the right solution but when submitting it to the website, it does not accept it.</p>
  
  <p>I tried debugging it by printing all the possible combinations and they're all done (horizontally, vertically and diagonally). The array is filled correctly also. I checked it by printing it after.</p>
  
  <p>Do you know where the problem may be?</p>
  
  <h2>Question</h2>
  
  <blockquote>
    <p>What is the greatest product of four adjacent numbers in the same
    direction (up, down, left, right, or diagonally) in the 20×20 grid?</p>
  </blockquote>
  
  <p><a href="https://projecteuler.net/problem=11" rel="noreferrer">Project Euler</a></p>
  
  <h2>Code</h2>
  
  <pre><code>String product = 
            "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 ";
  
  Scanner sc = new Scanner(product);
  int[][] in = new int[20][20];
  for (int i = 0 ; i &lt; 20 ; i++){
      for (int j = 0 ; j &lt; 20 ; j++){
          in[i][j] = sc.nextInt();
      }
  }
  
  int max = Integer.MIN_VALUE;
  int tmp = 0;
  
  for (int i = 0 ; i &lt; 20 ; i++){
      for (int j = 0 ; j &lt; 20 ; j++){
          if (i &lt; 17){
              tmp = in[i][j] * in[i+1][j] * in[i+2][j] * in[i+3][j];
              if (tmp &gt; max) max = tmp;
          }
          if (j &lt; 17){
              tmp = in[i][j] * in[i][j+1] * in[i][j+2] * in[i][j+3];
              if (tmp &gt; max) max = tmp;
          }
          if (j &lt; 17 &amp;&amp; i &lt; 17){
              tmp = in[i][j] * in[i+1][j+1] * in[i+2][j+2] * in[i+3][j+3];
              if (tmp &gt; max) max = tmp;
          }
      }
  }
  
  System.out.println(max);
  </code></pre>
  
  <h2>Output</h2>
  
  <pre><code>51267216
  </code></pre>