LFUcache

const LFUcache = (capacity) => {
	let box = {}
	box.cache = {}
	for (var i = 0; i<capacity; i++) {
		box[i] = [];
	}
	box.put = function (k, v) {
		if (box.cache.keys.length <capacity) {
			if (!(k in cache)) {
				var item = [k,v, 0]
				this[0].push(item);
				this.cache[k] = item;
			}  
		} else {
			let LFU = box[0].splice(box[0].length-1)
			delete box[LFU[0]]
		}
	}

	box.get = function(k) {
		let item = box.cache[k]
		if (item) {
			box[item[2]].splice(box[item[2]].indexOf(item))
			item[2] += 1;
			box[item[2]].unshift(item)
			return item
		} else {
			return -1
		}
		
	} 
}