JavaScript/Search/jumpSearch.js

/* The Jump Search algorithm allows to combine a linear search with a speed optimization.
  * This means that instead of going 1 by 1, we will increase the step of √n and increase that 
  * step of √n which make the step getting bigger and bigger.
  * The asymptotic analysis of Jump Search is o(√n). Like the binary search, it needs to be sorted.
  * The advantage against binary search is that Jump Search traversed back only once.
 */

const jumpSearch = (arr, value)=>{
  const length = arr.length;
  let step = Math.floor(Math.sqrt(length));
  let lowerBound = 0;
  while (arr[Math.min(step, length)-1] < value)
  {
    lowerBound = step;
    step += step;
    if (lowerBound >= length){
      return -1;
    }
  }
   
  const upperBound = Math.min(step, length);
  while (arr[lowerBound] < value)
  {
    lowerBound++;
    if (lowerBound === upperBound){
      return -1;
    }
  }
  if (arr[lowerBound] === value){
     return lowerBound;
  }
  return -1;
}
const arr = [0,0,4,7,10,23,34,40,55,68,77,90]
jumpSearch(arr,4);
jumpSearch(arr,34);
jumpSearch(arr,77);