Tries: Contacts

tries.js

// https://www.hackerrank.com/challenges/ctci-contacts


function Trie() {
    this.data = {};
}

Trie.prototype.process = function(op, str) {
    if(op === 'add') {
        let data = this.data;
        for(let char of str) {
            if(!data[char]) {
                data[char] = {count: 0}
            }
            data[char].count++;
            data = data[char];
        }
    }else if(op === 'find') {
        let data = this.data;
        for(let char of str) {
            if(typeof data[char] != 'undefined') {
                data = data[char];
            }else {
                console.log(0);
                return;
            }
        }

        console.log(data.count);
    }
}

Trie.prototype.dump = function() {
    console.log(this.data);
}

////////////////////

let input = `4
add hack
add hackerrank
find hac
find hak`;

let commands = input.split('\n').slice(1).map(line => line.split(' '));

let t = new Trie();
commands.forEach(command => t.process(command[0], command[1]));