_986.java

package com.fishercoder.solutions;

import java.util.ArrayList;
import java.util.List;

public class _986 {
    public static class Solution1 {
        public int[][] intervalIntersection(int[][] firstList, int[][] secondList) {
            int i = 0;
            int j = 0;
            List<int[]> list = new ArrayList<>();
            while (i < firstList.length && j < secondList.length) {
                int start = Math.max(firstList[i][0], secondList[j][0]);
                int end = Math.min(firstList[i][1], secondList[j][1]);
                if (start <= end) {
                    list.add(new int[]{start, end});
                }
                if (end == firstList[i][1]) {
                    i++;
                } else {
                    j++;
                }
            }
            return list.toArray(new int[list.size()][2]);
        }
    }
}