Binary Search vs Linear Search Real Cost Difference in DSA C++ - Interactive Comparison Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to perform a linear search for a target value in an array.

DSA C++

int linearSearch(int arr[], int n, int target) {
    for (int i = 0; i < n; i++) {
        if (arr[i] == [1]) {
            return i;
        }
    }
    return -1;
}

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

Ai

Btarget

Cn

Darr

Attempts:

3 left

💡 Hint

Common Mistakes

Using the loop index instead of the target value in the comparison.

Comparing with the array name instead of an element.

The code checks if the current element arr[i] equals the target value we are searching for.

2fill in blank

medium

Complete the code to perform a binary search on a sorted array.

DSA C++

int binarySearch(int arr[], int left, int right, int target) {
    while (left <= right) {
        int mid = left + (right - left) / 2;
        if (arr[mid] == [1]) {
            return mid;
        } else if (arr[mid] < target) {
            left = mid + 1;
        } else {
            right = mid - 1;
        }
    }
    return -1;
}

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

Amid

Bleft

Ctarget

Dright

Attempts:

3 left

💡 Hint

Common Mistakes

Comparing with the wrong variable like left or right indices.

Using the middle index instead of the target value.

The binary search compares the middle element arr[mid] with the target value to decide the next search range.

3fill in blank

hard

Fix the error in the binary search condition to correctly update the search range.

DSA C++

if (arr[mid] < [1]) {
    left = mid + 1;
} else {
    right = mid - 1;
}

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

Atarget

Bleft

Cright

Dmid

Attempts:

3 left

💡 Hint

Common Mistakes

Comparing with the left or right index instead of the target value.

Using the middle index instead of the target value.

The condition must compare arr[mid] with the target to decide which half to search next.

4fill in blank

hard

Fill both blanks to create a dictionary that maps each element to its index, then check if target exists.

DSA C++

std::unordered_map<int, int> indexMap;
for (int i = 0; i < n; i++) {
    indexMap[[1]] = i;
}
if (indexMap.find([2]) != indexMap.end()) {
    return indexMap[[2]];
} else {
    return -1;
}

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

Aarr[i]

Btarget

Ci

Darr

Attempts:

3 left

💡 Hint

Common Mistakes

Using the index i as the key instead of the element.

Checking the map with the index instead of the target.

The first blank should be the element arr[i] to map it to its index. The second blank is the target to check if it exists in the map.

5fill in blank

hard

Fill all three blanks to create a map comprehension that stores elements greater than 10 with their squares.

DSA C++

std::unordered_map<int, int> result;
for (int [1] = 0; [1] < [3]; [1]++) {
    if (arr[[1]] [2] 10) {
        result[arr[[1]]] = arr[[1]] * arr[[1]];
    }
}

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

Ai

B>

C<

Dn

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong comparison operator like <.

Using the wrong loop variable or loop condition.

The loop variable is i. The condition checks if the element is greater than 10 using >. The loop runs while i < n.