Given an integer row_count, return a list of lists representing the first row_count rows of Pascal's triangle. Each row starts and ends with 1, and each interior element is the sum of the two elements directly above it from the previous row.
Example 1
Input: 2
Output: [[1],[1,1]]
Explanation: The first two rows are [1] and [1,1].
Example 2
Input: 4
Output: [[1],[1,1],[1,2,1],[1,3,3,1]]
Explanation: The first four rows are constructed as per Pascal's triangle rules.
Constraints
Case 1
Input: 3
Expected: [[1],[1,1],[1,2,1]]
Case 2
Input: 6
Expected: [[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1],[1,5,10,10,5,1]]
Case 3
Input: 5
Expected: [[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]]