Программирование на С#

using System;

namespace q84182775 {
class Program {
static void Main(string[] args) {
Console.Write("n? ");
var n = int.Parse(Console.ReadLine());
int[,] a = new int[n, n];
var rnd = new Random();
Console.WriteLine("matrix:");
for (var r = 0; r < n; ++r) {
for (var c = 0; c < n; ++c) Console.Write("{0,4}", a[r, c] = rnd.Next(100));
Console.WriteLine();
}
for (var r = 0; r < n; ++r) {
var mc = 0;
for (var c = 1; c < n; ++c) if (a[r, c] > a[r, mc]) mc = c;
var t = a[r, r];
a[r, r] = a[r, mc];
a[r, mc] = t;
}
Console.WriteLine("result:");
for (var r = 0; r < n; ++r) {
for (var c = 0; c < n; ++c) Console.Write("{0,4}", a[r, c]);
Console.WriteLine();
}
Console.ReadKey();
}
}
}