HashTables
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class HashTable {
constructor(size){
this.data = new Array(size);
}
_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) {
let 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 = [];
for(let i = 0; i < this.data.length; i++) {
if(this.data[i]){
if(this.data[i].length === 1) {
keysArray.push(this.data[i][0][0]);
} else {
for(let j = 0; j < this.data[i].length; j++){
keysArray.push(this.data[i][j][0]);
}
}
}
}
return keysArray;
}
values(){
const valuesArray = [];
for(let i = 0; i < this.data.length; i++) {
if(this.data[i]){
if(this.data[i].length === 1) {
valuesArray.push(this.data[i][0][1]);
} else {
for(let j = 0; j < this.data[i].length; j++){
valuesArray.push(this.data[i][j][1]);
}
}
}
}
return valuesArray;
}
}
const myHashTable = new HashTable(1);
// myHashTable._hash('grapes')
myHashTable.set('grapes', 10000);
myHashTable.set('apples', 20);
myHashTable.set('oranges', 2);
console.log(myHashTable.keys());
console.log(myHashTable.values());
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