joi-2010-3.js

var fs = require('fs'),
	sys = require('sys');

var result = function (file) {
	fs.readFile(file, "utf-8", function (err, data) {
		err && sys.print(err)
		
		r = '';
		n = +data.split('\r\n')[0];
		max = +data.split('\r\n')[1];
		data.split('\r\n').forEach(function (val, i) {
			if (i < 2 || i > max+1) {
				return false;
			}
			var xy = val.split(' '),
				x = +xy[0],
				y = +xy[1],
				color = check(x, y, n);
			r += color+'\n';
		})
		
		fs.writeFile(file, r);
	});
}

function check (x, y, n) {
	if (y > n/2) y = n-y+1;
	if (x > n/2) x = n-x+1;
	return (x >= y+1 && x <= n-y) ? (y%3 || 3) : (x%3 || 3);
}

result('2011-yo-t3-in1.txt')
result('2011-yo-t3-in2.txt')
result('2011-yo-t3-in3.txt')
result('2011-yo-t3-in4.txt')
result('2011-yo-t3-in5.txt')