Binary Search Iterative Approach in DSA Typescript - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the middle index in the binary search loop.

DSA Typescript

let mid = Math.floor((low + [1]) / 2);

Drag options to blanks, or click blank then click option'

Ahigh

Blow

Cmid

Darray.length

Attempts:

3 left

💡 Hint

Common Mistakes

Using mid instead of high causes incorrect calculation.

Using array.length instead of high leads to wrong index.

The middle index is calculated by taking the floor of the average of low and high indices.

2fill in blank

medium

Complete the code to update the low index when the target is greater than the middle element.

DSA Typescript

if (target > arr[mid]) {
  low = [1];
}

Drag options to blanks, or click blank then click option'

Amid + 1

Bhigh

Clow + 1

Dmid

Attempts:

3 left

💡 Hint

Common Mistakes

Setting low to mid causes infinite loop.

Setting low to high skips elements.

When the target is greater than the middle element, we move the low index to mid + 1 to search the right half.

3fill in blank

hard

Fix the error in the loop condition to correctly continue searching while low is less than or equal to high.

DSA Typescript

while (low [1] high) {
  // binary search steps
}

Drag options to blanks, or click blank then click option'

A>

B!=

C<=

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using < misses checking when low equals high.

Using != can cause infinite loops.

The loop should continue while low is less than or equal to high to cover all elements.

4fill in blank

hard

Fill both blanks to correctly update the high index when the target is less than the middle element.

DSA Typescript

if (target < arr[mid]) {
  high = [1];
  low = [2];
}

Drag options to blanks, or click blank then click option'

Amid - 1

Bmid + 1

Clow

Dhigh

Attempts:

3 left

💡 Hint

Common Mistakes

Setting low to mid + 1 skips elements.

Setting high to low causes errors.

When target is less than middle element, high moves to mid - 1 and low stays the same.

5fill in blank

hard

Fill all three blanks to complete the binary search function that returns the index of the target or -1 if not found.

DSA Typescript

function binarySearch(arr: number[], target: number): number {
  let low = 0;
  let high = arr.length - 1;
  while (low [1] high) {
    let mid = Math.floor((low + high) / 2);
    if (arr[mid] === target) {
      return [2];
    } else if (target < arr[mid]) {
      high = mid - 1;
    } else {
      low = mid + 1;
    }
  }
  return [3];
}

Drag options to blanks, or click blank then click option'

A<=

Bmid

C-1

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using < in loop misses last element.

Returning low or high instead of mid is wrong.

Returning 0 instead of -1 when not found.

The loop condition is low <= high. Return mid if found, else return -1 if not found.