LeetCode118杨辉三角

给定一个非负整数 numRows，生成杨辉三角的前 numRows 行。

在杨辉三角中，每个数是它左上方和右上方的数的和。

示例:

输入: 5
输出:
[
     [1],
    [1,1],
   [1,2,1],
  [1,3,3,1],
 [1,4,6,4,1]
]

/**
 * 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) {
    int i, j;
    if(numRows == 0) return 0;
    
    int** Array = (int **)malloc(numRows * sizeof(int *));
    *columnSizes = (int *)malloc(numRows * sizeof(int));
    for(i = 0; i < numRows; i++){
        (*columnSizes)[i] = i + 1;
        Array[i] = (int *)malloc((i + 1) * sizeof(int));
        for(j = 0; j < i + 1; j++){
            if((j == 0) || (j == i))
                Array[i][j] = 1;
            else
                Array[i][j] = Array[i - 1][j - 1] + Array[i - 1][j];
        }
    }
    return Array;
}