Longest Common Prefix

var longestCommonPrefix = function(strs) {
    if (strs.length < 1) {
        return "";
    }

    var prefix = strs[0];

    for (var i = 1; i < strs.length; i++) {
        if (prefix.length < 1) {
            return "";
        }

        var len = prefix.length < strs[i].length ? prefix.length : strs[i].length;

        for (var j = 0; j < len; j++) {
            if (prefix[j] != strs[i][j]) {
                break;
            }
        }

        prefix = prefix.substr(0, j);
    }

    return prefix;
};