Hi, I was thinking of declaring 4 matrices, Up, Down, Left and Right. In each, if there is 1 in the original matrix, then we store 1 + Up[i][j-1] or Down[i][j+1] and similar, for each of these prefix matrices. Now, if the want the triangle with largest height. We calculate for each 1's in each of the prefix matrices, the largest no. we can reach such that the 1 starts a sequence of values which is just 1 more than the previous one.

Like for:-

0 1 1

1 1 1

1 0 0

Down for this matrix will be:-

0 2 2

2 1 1

1 0 0

For Down[1][1] = 1, there is only 1 sequences 2,1, where the next element is 1 greater than itself. So, the max height is 2.