Click here to Skip to main content
14,331,896 members

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

shekarchee asked:

Open original thread
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();

           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];

          double time = timer.ElapsedMilliseconds;
Tags: C#


When answering a question please:
  1. Read the question carefully.
  2. Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
  3. If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
  4. Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.
Let's work to help developers, not make them feel stupid.
Please note that all posts will be submitted under the The Code Project Open License (CPOL).

CodeProject, 503-250 Ferrand Drive Toronto Ontario, M3C 3G8 Canada +1 416-849-8900 x 100