Day11.java

//Problem:Pascal's Triangle
//https://leetcode.com/problems/pascals-triangle/
class Solution {
    public List<List<Integer>> generate(int numRows) {
               List<List<Integer>> result = new ArrayList<>();
        if (numRows == 0) {
            return result;
        }

        List<Integer> firstRow = new ArrayList<>();
        firstRow.add(1);
        result.add(firstRow);

        for (int i = 1; i < numRows; i++) {
            List<Integer> prevRow = result.get(i - 1);
            List<Integer> currentRow = new ArrayList<>();
            currentRow.add(1);

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

            currentRow.add(1);
            result.add(currentRow);
        }

        return result;
    }
}