1656-design-an-ordered-stream.js

/**
 * @param {number} n
 */
const OrderedStream = function(n) {
  this.arr = Array(n + 1)
  this.ptr = 1
};

/** 
 * @param {number} id 
 * @param {string} value
 * @return {string[]}
 */
OrderedStream.prototype.insert = function(id, value) {
  
  this.arr[id] = value
  const res = []
  let i
  for(i = this.ptr, len = this.arr.length; i < len; i++) {
    if (this.arr[i] != null) res.push(this.arr[i])
    else {
      break
    }
  }
  this.ptr = i
    
  return res
};

/** 
 * Your OrderedStream object will be instantiated and called as such:
 * var obj = new OrderedStream(n)
 * var param_1 = obj.insert(id,value)
 */