Binary Search

Find the index of an element in a sorted array using binary search with O(log n) time complexity.

Code

Algorithms

let lo = 0, hi = arr.length - 1, result = -1;
while (lo <= hi) {
  const mid = Math.floor((lo + hi) / 2);
  if (arr[mid] === target) { result = mid; break; }
  else if (arr[mid] < target) lo = mid + 1;
  else hi = mid - 1;
}
return result;

Parameters

arr(array)

Sorted array

target(number)

Element to find

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