How to search in a row wise increased matrix using C#?

Csharp Server Side Programming Programming

The primitive solution for this problem is to scan all elements stored in the input matrix to search for the given key. This linear search approach costs O(MN) time if the size of the matrix is MxN.

The matrix needs to be scanned from the top right, if the search element is greater than the top right element then increments the row or else decrement the column. The below piece of code develops a function SearchRowwiseIncrementedMatrix that takes a two-dimensional array and search key as input and returns either true or false depending upon the success or failure of search key found.

Code

public class Matrix{
   public bool SearchRowwiseIncrementedMatrix(int[,] mat, int searchElement){
      int row = getMatrixRowSize(mat);
      int col = getMatrixColSize(mat) - 1;
      int r = 0;

      while (col >= 0 && r < row){
         if (mat[r, col] == searchElement){
            return true;
         }
         else if (searchElement < mat[r, col]){
            col--;
         }
         else{
            r++;
         }
      }
      return false;
   }

   private int getMatrixRowSize(int[,] mat){
      return mat.GetLength(0);
   }
   private int getMatrixColSize(int[,] mat){
      return mat.GetLength(1);
   }
}

static void Main(string[] args){
   Matrix m = new Matrix();
   int[,] mat = new int[3, 4] { { 1, 7, 10, 19 }, { 2, 8, 11, 20 }, { 3, 9, 12, 21 } };
   Console.WriteLine(m.SearchRowwiseIncrementedMatrix(mat, 11));
}

Output

TRUE

Nizamuddin Siddiqui

Published on 17-Aug-2021 06:46:07

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