Interval List Intersections — LeetCode May Challenge Day 23

In this problem, we are given 2 sets of various pairs of numbers. Each pair in each set is an interval. We are asked to find the intersections/overlaps of the two sets.

// What we need to do here is simply find the overlapping times between two sets of times we then repeat it for every element. First we create a list to store all the time intervals that we determine to be overlapping
class Solution {
    public int[][] intervalIntersection(int[][] A, int[][] B) {
        List<int[] > list = new ArrayList<>();
        for( int a = 0, b = 0; a < A.length && b < B.length; ){
            // Find out which starts later
            int start = Math.max(A[a][0],B[b][0]); 
            
            // Find out which ends earlier
            int end = Math.min(A[a][1],B[b][1]); 
            // Since start is less than or equal to end, this means         
            over lap exists
            if( start <= end ) list.add(new int[] {start,end});
                
// This checks if we need to move to next element on the A list or the B list if the end of A is less than end of B then we no longer need to check for that A element because the array is sorted .. else we move on to next element.
            
            if (A[a][1] < B[b][1]){
                a++;
            } else{
                b++;
            }
        }
        return list.toArray(new int[list.size()][]);
    }
}

Video:

Thank you!