Leetcode 57 - insert intervals - code review on June 29, 2017

Leetcode57_InsertIntervals_codereview.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _57InsertIntervals
{
    /// <summary>
    /// Leetcode 57 
    /// https://leetcode.com/problems/insert-interval/?tab=Description#/description
    /// code review on June 29, 2017 
    /// source code reference:
    /// http://simpleandstupid.com/2014/10/29/insert-interval-leetcode-%E8%A7%A3%E9%A2%98%E7%AC%94%E8%AE%B0/
    /// </summary>
    public class Interval
    {
        public int start;
        public int end;
        public Interval()
        {
            start = 0;
            end = 0;
        }

        public Interval(int s, int e)
        {
            start = s;
            end = e;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
        }

        /*
         * Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).
            You may assume that the intervals were initially sorted according to their start times.
            Example 1:
            Given intervals [1,3],[6,9], insert and merge [2,5] in as [1,5],[6,9].
            Example 2:
            Given [1,2],[3,5],[6,7],[8,10],[12,16], insert and merge [4,9] in as [1,2],[3,10],[12,16].
            This is because the new interval [4,9] overlaps with [3,5],[6,7],[8,10].
         */
        // public IList<Interval> Insert(IList<Interval> intervals, Interval newInterval) {

        public static IList<Interval> insert(IList<Interval> intervals, Interval newInterval)
        {
            var result = new List<Interval>();

            foreach (var interval in intervals)
            {
                if (interval.end < newInterval.start)
                {
                    result.Add(interval);
                }
                else if (interval.start > newInterval.end)
                {
                    result.Add(newInterval);
                    newInterval = interval;
                }
                else if (interval.end  >= newInterval.start ||
                        interval.start <= newInterval.end)
                {
                    newInterval = new Interval(
                        Math.Min(interval.start, newInterval.start),
                        Math.Max(newInterval.end, interval.end));
                }
            }

            result.Add(newInterval);

            return result;
        }        
    }
}