Task: Conway's Game of Life
C: #include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#define for_x for (int x = 0; x < w; x++)
#define for_y for (int y = 0; y < h; y++)
#define for_xy for_x for_y
void show(void *u, int w, int h)
{
	int (*univ)[w] = u;
	printf("\033[H");
	for_y {
		for_x printf(univ[y][x] ? "\033[07m  \033[m" : "  ");
		printf("\033[E");
	}
	fflush(stdout);
}

void evolve(void *u, int w, int h)
{
	unsigned (*univ)[w] = u;
	unsigned new[h][w];

	for_y for_x {
		int n = 0;
		for (int y1 = y - 1; y1 <= y + 1; y1++)
			for (int x1 = x - 1; x1 <= x + 1; x1++)
				if (univ[(y1 + h) % h][(x1 + w) % w])
					n++;

		if (univ[y][x]) n--;
		new[y][x] = (n == 3 || (n == 2 && univ[y][x]));
	}
	for_y for_x univ[y][x] = new[y][x];
}

void game(int w, int h)
{
	unsigned univ[h][w];
	for_xy univ[y][x] = rand() < RAND_MAX / 10 ? 1 : 0;
	while (1) {
		show(univ, w, h);
		evolve(univ, w, h);
		usleep(200000);
	}
}

int main(int c, char **v)
{
	int w = 0, h = 0;
	if (c > 1) w = atoi(v[1]);
	if (c > 2) h = atoi(v[2]);
	if (w <= 0) w = 30;
	if (h <= 0) h = 30;
	game(w, h);
}

C#: using System;
using System.Text;
using System.Threading;
 
namespace ConwaysGameOfLife
{
    
    class Program
    {
        
        private const int DELAY = 50;
 
        
        private const ConsoleColor DEAD_COLOR = ConsoleColor.White;
        private const ConsoleColor LIVE_COLOR = ConsoleColor.Black;
 
        
        private const ConsoleColor EXTRA_COLOR = ConsoleColor.Gray;
 
        private const char EMPTY_BLOCK_CHAR = ' ';
        private const char FULL_BLOCK_CHAR = '\u2588';
 
        
        private static bool[,] board;
 
        
        private static int width = 32;
        private static int height = 32;
 
        
        private static bool loopEdges = true;
 
 
        static void Main(string[] args)
        {
            
            initializeDemoBoard();
 
            initializeConsole();
 
            
            while (!Console.KeyAvailable || Console.ReadKey(true).Key != ConsoleKey.Escape) {
                Program.drawBoard();
                Program.updateBoard();
 
                
                Thread.Sleep(DELAY);
            }
        }
 
        
        private static void initializeConsole()
        {
            Console.BackgroundColor = EXTRA_COLOR;
            Console.Clear();
 
            Console.CursorVisible = false;
 
            
            
            int width = Math.Max(Program.width, 8) * 2 + 1;
            int height = Math.Max(Program.height, 8) + 1;
            Console.SetWindowSize(width, height);
            Console.SetBufferSize(width, height);
 
            Console.BackgroundColor = DEAD_COLOR;
            Console.ForegroundColor = LIVE_COLOR;
        }
 
        
        private static void initializeRandomBoard()
        {
            var random = new Random();
 
            Program.board = new bool[Program.width, Program.height];
            for (var y = 0; y < Program.height; y++) {
                for (var x = 0; x < Program.width; x++) {
                    
                    Program.board[x, y] = random.Next(2) == 0;
                }
            }
        }
 
        
        private static void initializeDemoBoard()
        {
            Program.width = 3;
            Program.height = 3;
 
            Program.loopEdges = false;
 
            Program.board = new bool[3, 3];
            Program.board[1, 0] = true;
            Program.board[1, 1] = true;
            Program.board[1, 2] = true;
        }
 
        
        private static void drawBoard()
        {
            
            var builder = new StringBuilder();
 
            for (var y = 0; y < Program.height; y++) {
                for (var x = 0; x < Program.width; x++) {
                    char c = Program.board[x, y] ? FULL_BLOCK_CHAR : EMPTY_BLOCK_CHAR;
 
                    
                    builder.Append(c);
                    builder.Append(c);
                }
                builder.Append('\n');
            }
 
            
            Console.SetCursorPosition(0, 0);
            Console.Write (builder.ToString());
        }
 
        
        private static void updateBoard()
        {
            
            bool[,] newBoard = new bool[Program.width, Program.height];
 
            for (var y = 0; y < Program.height; y++) {
                for (var x = 0; x < Program.width; x++) {
                    var n = countLiveNeighbors(x, y);
                    var c = Program.board[x, y];
 
                    
                    
                    newBoard[x, y] = c && (n == 2 || n == 3) || !c && n == 3;
                }
            }
 
            
            Program.board = newBoard;
        }
 
        
        private static int countLiveNeighbors(int x, int y)
        {
            
            int value = 0;
 
            
            for (var j = -1; j <= 1; j++) {
                
                if (!Program.loopEdges && y + j < 0 || y + j >= Program.height) {
                    continue;
                }
 
                
                int k = (y + j + Program.height) % Program.height;
 
                for (var i = -1; i <= 1; i++) {
                    
                    if (!Program.loopEdges && x + i < 0 || x + i >= Program.width) {
                        continue;
                    }
 
                    
                    int h = (x + i + Program.width) % Program.width;
 
                    
                    value += Program.board[h, k] ? 1 : 0;
                }
            }
 
            
            return value - (Program.board[x, y] ? 1 : 0);
        }
    }
}