Pascal's Triangle

Given numRows, generate the first numRows of Pascal's triangle.

For example, given numRows = 5,
Return

[
     [1],
    [1,1],
   [1,2,1],
  [1,3,3,1],
 [1,4,6,4,1]
]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

/** * Return an array of arrays. * The sizes of the arrays are returned as *columnSizes array. * Note: Both returned array and *columnSizes array must be malloced, assume caller calls free(). */ int** generate(int numRows, int** columnSizes) { if(numRows == 0) return NULL; int **result = (int **)malloc(numRows * sizeof(int *)); (*columnSizes) = (int *)malloc(numRows * sizeof(int)); int i, j; for (i = 0; i < numRows; i++) { (*columnSizes)[i] = i + 1; result[i] = (int *)malloc((*columnSizes)[i] * sizeof(int)); result[i][0] = 1; for (j = 1; j < i; j++) { result[i][j] = result[i - 1][j - 1] + result[i - 1][j]; } result[i][i] = 1; } return result; }