aoc8

allowed = ["abcefg", "cf", "acdeg", "acdfg", "bcdf", "abdfg", "abdefg", "acf", "abcdefg", "abcdfg"];
letters = "abcdefg";
arr = document.getElementsByTagName("pre")[0].innerText.split("\n").filter(function(n){return n;});

permute = function(str, fun) {
	if (!str) {
		return fun(str);
	}
	str.split("").forEach(function(c) {
		permute(str.replace(c, ""), function(sub) {fun(c + sub)});
	});
}

arr.map(function(row) {
	options = row.split(" | ")[0].split(" ");
	digits  = row.split(" | ")[1].split(" ");
	foundVersion = "";
	permute(letters, function(version) {
		if (!options.find(function(option) {
			return allowed.indexOf(
				option.split("").map(function(c) {return version[letters.indexOf(c)]}).sort(function(a,b){return letters.indexOf(a)-letters.indexOf(b)}).join(""))<0;
		})) {
			foundVersion = version;
		}
	});
	return parseInt(digits.map(function(digit) {
		return allowed.indexOf(
				digit.split("").map(function(c) {return foundVersion[letters.indexOf(c)]}).sort(function(a,b){return letters.indexOf(a)-letters.indexOf(b)}).join(""));
	}).join(""));
}).reduce(function(a,b) {return a+b})