unhash.js

function unhash(hash) {
    var parts = [];
    var letters = 'acdegilmnoprstuw';
    while (hash !== 7) {
        var index = hash % 37;
        hash = (hash - index) / 37;
        parts.unshift(letters[index]);
    }
    return parts.join('');
}

function hash(str) {
    var h = 7;
    var letters = 'acdegilmnoprstuw';
    for (var i = 0, len = str.length; i < len; i++) {
        h = (h * 37 + letters.indexOf(str[i]))
    }
    return h;
}

/*
Write code to find a 7 letter string of characters that contains only letters from

acdegilmnoprstuw

such that the hash(the_string) is

675202166929

if hash is defined by the following pseudo-code:

Int64 hash (String s) {
    Int64 h = 7
    String letters = "acdegilmnoprstuw"
    for(Int32 i = 0; i < s.length; i++) {
        h = (h * 37 + letters.indexOf(s[i]))
    }
    return h
}
For example, if we were trying to find the 7 letter string where hash(the_string) was 680131659347, the answer would be "leepadg".
*/