[Programming Problem] Time Based Key-Value Store

/**
 * Initialize your data structure here.
 */
 
var closest = function(i, j, arr, val) {
    if ( i > j ) return {value: '', timestamp: Number.MAX_VALUE};
 
    let mid = i + Math.round((j-i)/2);
    if ( arr[mid].timestamp === val ) return arr[mid];
 
    let ret = Number.MAX_VALUE;
    if ( arr[mid].timestamp > val )
        ret = closest(i, mid-1, arr, val);
    else 
        ret = closest(mid+1, j, arr, val);
 
    if ( arr[mid].timestamp < val && ret.timestamp < val ) {
        return arr[mid].timestamp > val ? arr[mid] : ret;
    } else if ( arr[mid].timestamp < val ) {
        return arr[mid];
    } else {
        return ret;
    }
}
 
 
var TimeMap = function() {
    this.map = {};
};
 
/** 
 * @param {string} key 
 * @param {string} value 
 * @param {number} timestamp
 * @return {void}
 */
TimeMap.prototype.set = function(key, value, timestamp) {
    if (!this.map[key]) this.map[key] = [];
    this.map[key].push({value, timestamp});
};
 
/** 
 * @param {string} key 
 * @param {number} timestamp
 * @return {string}
 */
TimeMap.prototype.get = function(key, timestamp) {
    if (!this.map[key]) return "";
    let arr = this.map[key];
    let ret = closest(0, arr.length-1, arr, timestamp);
    return ret.value;
};
 
/** 
 * Your TimeMap object will be instantiated and called as such:
 * var obj = new TimeMap()
 * obj.set(key,value,timestamp)
 * var param_2 = obj.get(key,timestamp)
 */

/** * Initialize your data structure here. */ var closest = function(i, j, arr, val) { if ( i > j ) return {value: '', timestamp: Number.MAX_VALUE}; let mid = i + Math.round((j-i)/2); if ( arr[mid].timestamp === val ) return arr[mid]; let ret = Number.MAX_VALUE; if ( arr[mid].timestamp > val ) ret = closest(i, mid-1, arr, val); else ret = closest(mid+1, j, arr, val); if ( arr[mid].timestamp < val && ret.timestamp < val ) { return arr[mid].timestamp > val ? arr[mid] : ret; } else if ( arr[mid].timestamp < val ) { return arr[mid]; } else { return ret; } } var TimeMap = function() { this.map = {}; }; /** * @param {string} key * @param {string} value * @param {number} timestamp * @return {void} */ TimeMap.prototype.set = function(key, value, timestamp) { if (!this.map[key]) this.map[key] = []; this.map[key].push({value, timestamp}); }; /** * @param {string} key * @param {number} timestamp * @return {string} */ TimeMap.prototype.get = function(key, timestamp) { if (!this.map[key]) return ""; let arr = this.map[key]; let ret = closest(0, arr.length-1, arr, timestamp); return ret.value; }; /** * Your TimeMap object will be instantiated and called as such: * var obj = new TimeMap() * obj.set(key,value,timestamp) * var param_2 = obj.get(key,timestamp) */