0119 - Pascal's Triangle II

0119 - Pascal's Triangle II

Given an integer rowIndex, return the rowIndexth (0-indexed) row of the Pascal's triangle.

In Pascal's triangle, each number is the sum of the two numbers directly above it as shown:

Examples

Input: rowIndex = 3 Output: [1,3,3,1]

Input: rowIndex = 0 Output: [1]

Input: rowIndex = 1 Output: [1,1]

Constraints

• 0 <= rowIndex <= 33

Java Solution

class Solution {
  public List<Integer> getRow(int rowIndex) {
    List<Integer> curr = new ArrayList<>();
    List<Integer> prev = new ArrayList<>();
    curr.add(1);
    prev.add(1);


    for (int i = 1; i <= rowIndex; i++) {
        curr =  new ArrayList<>();
        curr.add(1);

        for (int j = 1; j < i; j++) {
          curr.add(prev.get(j - 1) + prev.get(j));
        }

        curr.add(1);
        prev = curr;
    }
      
    return prev;
  }
}