56. Merge Intervals

Input: [[1,3],[2,6],[8,10],[15,18]]
Output: [[1,6],[8,10],[15,18]]
Explanation: Since intervals [1,3] and [2,6] overlaps, merge them into [1,6].

Input: [[1,4],[4,5]]
Output: [[1,5]]
Explanation: Intervals [1,4] and [4,5] are considered overlapping.

class Solution {
    public int[][] merge(int[][] intervals) {
        List<int[]> list = new ArrayList<>();
        
        Collections.sort(Arrays.asList(intervals), Comparator.comparingInt(p -> p[0]));
        
        if(intervals.length > 1){
            for(int i=1; i<intervals.length; i++){
                if(intervals[i-1][1] >= intervals[i][0]){
                    int min = Math.min(intervals[i-1][0], intervals[i][0]);
                    int max = Math.max(intervals[i-1][1], intervals[i][1]);
                    
                    intervals[i-1][0] = intervals[i][0] = min;
                    intervals[i-1][1] = intervals[i][1] = max;
                }else{
                    list.add(intervals[i-1]);
                }
            }
        }
        if(intervals.length > 0){
            list.add(intervals[intervals.length-1]);
        }
        
        int[][] result = new int[list.size()][2];
        for(int i=0; i<list.size(); i++){
            int[] p = list.get(i);
            result[i][0] = p[0];
            result[i][1] = p[1];
        }
        
        return result;
    }
}

[문제] https://leetcode.com/problems/merge-intervals/