Esempio n. 1
0
        //Leetcode 1024: Stiching Video
        //You are given a series of video clips from a sporting event that lasted T seconds.  These video clips can be overlapping with each other and have varied lengths.

        //        Each video clip clips[i] is an interval: it starts at time clips[i][0] and ends at time clips[i][1].  We can cut these clips into segments freely: for example, a clip[0, 7] can be cut into segments[0, 1] + [1, 3] + [3, 7].

        //Return the minimum number of clips needed so that we can cut the clips into segments that cover the entire sporting event ([0, T]).  If the task is impossible, return -1.



        //Example 1:

        //Input: clips = [[0,2],[4,6],[8,10],[1,9],[1,5],[5,9]], T = 10
        //Output: 3
        //Explanation:
        //We take the clips [0,2], [8,10], [1,9]; a total of 3 clips.
        //Then, we can reconstruct the sporting event as follows:
        //We cut [1,9]
        //        into segments [1,2] + [2,8] + [8,9].
        //Now we have segments [0,2] + [2,8] + [8,10]
        //        which cover the sporting event [0, 10].

        //Example 2:

        //Input: clips = [[0,1],[1,2]], T = 5
        //Output: -1
        //Explanation:
        //We can't cover [0,5] with only [0,1] and [0,2].
        public int VideoStitching2(int[][] clips, int T)
        {
            if (clips.Length == 0)
            {
                return(-1);
            }
            IComparer <int[]> myComparer = new ReverseComparer();;

            Array.Sort(clips, myComparer);

            int start = clips[0][0], end = clips[0][1], i = 1, count = 1;

            if (start > 0)
            {
                return(-1);
            }
            else if (end >= T)
            {
                return(1);
            }
            while (i < clips.Length && end < T && clips[i][0] <= end)
            {
                int max = end;
                while (i < clips.Length && clips[i][0] <= end)
                {
                    max = Math.Max(max, clips[i][1]);
                    i++;
                }
                end = max;
                count++;
            }
            return(end >= T? count : -1);
        }
Esempio n. 2
0
        public int VideoStitching(int[][] clips, int T)
        {
            if (clips.Length == 0)
            {
                return(-1);
            }
            IComparer <int[]> myComparer = new ReverseComparer();;

            Array.Sort(clips, myComparer);

            int start = clips[0][0], end = clips[0][1];
            int max = end, count = 1;
            int current = 1;

            if (start > 0)
            {
                return(-1);
            }
            else if (end >= T)
            {
                return(1);
            }
            while (current < clips.Length && max < T && clips[current][0] <= end)
            {
                while (current < clips.Length && clips[current][0] <= end) // there is still overlap
                {
                    if (clips[current][1] > max)
                    {
                        max = clips[current][1];
                    }
                    current++;
                }

                count++;// we need another clip
                end = max;
            }

            if (max >= T)
            {
                return(count);
            }
            else
            {
                return(-1);
            }
        }