3.4 MatrixMaxElement

using System;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            const int size = 10;
            int[,] matrix = new int[size, size];
            matrix[2, 7] = 10;
            matrix[3, 1] = 99;
            matrix[5, 5] = 154;
            Console.WriteLine("Исходная матрица");
            int max = matrix[0, 0], k = 0, m = 0;
            foreach (int x in matrix)
            {
                Console.Write(x + " ");
            }
            for (int i = 0; i < size; i++)
                for (int j = 0; j < size; j++)
                    if (matrix[i, j] > max)
                    {
                        max = matrix[i, j];
                        k = i;
                        m = j;
                    }
            Console.WriteLine();
            Console.WriteLine("Максимальный элемент = " + max);
            matrix[k, m] = 0;
            Console.WriteLine("Новая матрица, с заменой на 0 ");

            foreach (int x in matrix)
            {
                Console.Write(x + " ");


            }

        }
    }
}