js实现trie树

function Node(options) {
    options = options || {};
    this.val = options.val;
    this.isCapital = null;
    this.position = options.position;
}

function position(str) {
    var code = str.charCodeAt(0);
    if (code >= 65 && code <= 97) {
        return {
            isCapital: false,
            position: code
        };
    } else if (code >= 97 && code <= 122) {
        return {
            isCapital: true,
            position: code
        };
    }
}
function makeTree(arr) {
    var i = 0;
    var j = 0;
    var root = new Node();
    var currentNode = root;
    while(i < arr.length) {
        var str = arr[i];
        while(j < str.length) {
            var info = position(str[j]);
            info.val = str[j];
            if (!currentNode[info.position]) {
                var node = new Node(info);
                currentNode[info.position] = node;
            }

            currentNode = currentNode[info.position];
            j++;
        }
        currentNode.isEnd= true;
        currentNode = root;
        i++;
        j = 0;
    }
    return root;
}

var str = ['hello', 'hel'];
function start() {
     root = makeTree(str);
}
start()