0057-insert-interval.cs

public class Solution {
    public int[][] Insert(int[][] intervals, int[] newInterval) {
        var result = new List<int[]>();
        
        for(var i = 0; i < intervals.Length; i++) {
            if(newInterval[1] < intervals[i][0]) {
                result.Add(newInterval);
                result.AddRange(
                    intervals.AsEnumerable().Skip(i).ToArray());
                
                return result.ToArray();
            }
            else if(newInterval[0] > intervals[i][1]) {
                result.Add(intervals[i]);
            } else {
                newInterval[0] = Math.Min(intervals[i][0], newInterval[0]);
                newInterval[1] = Math.Max(intervals[i][1], newInterval[1]);
            }
        }
        
        result.Add(newInterval);
        
        return result.ToArray();
    }
}