day5.js

var diff = 'a'.codePointAt(0) - 'A'.codePointAt(0);
var N = 'z'.codePointAt(0) - 'a'.codePointAt(0);
fs.readFile('05_input', 'utf8', function (err, _contents) 
{
	max = 1111111;

	for (aa = 0; aa < N; ++aa) {
		l = String.fromCodePoint(aa + 'a'.codePointAt(0));
		l2 = String.fromCodePoint(aa + 'A'.codePointAt(0));
		contents = _contents.replace(new RegExp(l, 'g'), '');
		contents = contents.replace(new RegExp(l2, 'g'), '').split``;
		console.log(contents.length + ' ' + _contents.length);


		i = 1;
		while (i < contents.length) {
			if (Math.abs(contents[i - 1].codePointAt(0) - contents[i].codePointAt(0)) == diff) {
				contents.splice(i - 1, 2);
				--i;
				if (i < 1) i = 1;
			} else {
				++i;
			}
		}

		if (contents.length < max)
			max = contents.length;
	}

});