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finding local minimum of a NxN matrix with algorithm of order N as worst case

shekarchee asked:

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How do I find the local minimum of a NxN matrix without and O N^2 algorithm as below. The time takes for ever when N grows large. I need the algorithm to b order N as its worst case.

int row = 0;
           int column = 0;
           Random random = new Random();


           int[,] matrix = new int[10, 10];
           for (int r = 0; r < 10; r++)
           {
                for (int c = 0; c < 10; c++)
                {
                     int randomNumber = random.Next(0, 100);
                     matrix[r, c] = randomNumber;
                }
           }


           int min = 100;
           Stopwatch timer = new Stopwatch();
           timer.Start();

           for (int i = 0; i < matrix.GetLongLength(0); i++)
           {
                for (int j = 0; j < matrix.GetLongLength(1); j++)
                {
                     if (matrix[i, j] < min)
                     {
                          min = matrix[i, j];
                     }

                }
           }
           timer.Stop();
          double time = timer.ElapsedMilliseconds;
          Console.WriteLine(time);
Tags: C#

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