class HashTable {
constructor(size){
this.data = new Array(size);
// this.data = [];
}
_hash(key) {
let hash = 0;
for (let i =0; i < key.length; i++){
hash = (hash + key.charCodeAt(i) * i) % this.data.length
}
return hash;
}
set(key, value) {
let address = this._hash(key);
if (!this.data[address]) {
this.data[address] = [];
}
this.data[address].push([key, value]);
return this.data;
}
get(key){
const address = this._hash(key);
const currentBucket = this.data[address]
if (currentBucket) {
for(let i = 0; i < currentBucket.length; i++){
if(currentBucket[i][0] === key) {
return currentBucket[i][1]
}
}
}
return undefined;
}
keys(){
const keysArray = [];
console.log(this.data.length);
for (let i = 0; i < this.data.length; i++){
if(this.data[i]){
keysArray.push(this.data[i][0][0])
}
}
return keysArray;
}
}
const myHashTable = new HashTable(50);
myHashTable.set('grapes', 10000)
myHashTable.set('grapes', 10000)
myHashTable.get('grapes')
myHashTable.set('apples', 9)
myHashTable.get('apples')
myHashTable.keys()
// keys() {
// if (!this.data.length) {
// return undefined
// }
// let result = []
// // loop through all the elements
// for (let i = 0; i < this.data.length; i++) {
// // if it's not an empty memory cell
// if (this.data[i] && this.data[i].length) {
// // but also loop through all the potential collisions
// if (this.data.length > 1) {
// for (let j = 0; j < this.data[i].length; j++) {
// result.push(this.data[i][j][0])
// }
// } else {
// result.push(this.data[i][0])
// }
// }
// }
// return result;
// }
//Google Question
//Given an array = [2,5,1,2,3,5,1,2,4]:
//It should return 2
//Given an array = [2,1,1,2,3,5,1,2,4]:
//It should return 1
//Given an array = [2,3,4,5]:
//It should return undefined
function firstRecurringCharacter(input) {
for (let i = 0; i < input.length; i++) {
for (let j = i + 1; j < input.length; j++) {
if(input[i] === input[j]) {
return input[i];
}
}
}
return undefined
}
function firstRecurringCharacter2(input) {
let map = {};
for (let i = 0; i < input.length; i++) {
if (map[input[i]] !== undefined) {
return input[i]
} else {
map[input[i]] = i;
}
}
return undefined
}
firstRecurringCharacter2([1,5,5,1,3,4,6])
//Bonus... What if we had this:
// [2,5,5,2,3,5,1,2,4]
// return 5 because the pairs are before 2,2
