Linear Search Algorithm in DSA C++ - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to return the index of the target element in the array or -1 if not found.

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[i]

Attempts:

3 left

💡 Hint

Common Mistakes

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

Comparing arr[i] to itself instead of the target.

The code compares each element arr[i] with the target to find a match.

2fill in blank

medium

Complete the code to loop through the array correctly for linear search.

DSA C++

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

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

Ai

Btarget

Carr

Dn

Attempts:

3 left

💡 Hint

Common Mistakes

Using the target value as the loop limit.

Using the loop index variable as the limit.

The loop should run from 0 to n - 1 to cover all elements.

3fill in blank

hard

Fix the error in the return statement to indicate the target was not found.

DSA C++

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

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

A-1

B0

Ci

Dn

Attempts:

3 left

💡 Hint

Common Mistakes

Returning the loop index i after the loop ends.

Returning zero which could be a valid index.

Returning -1 indicates the target was not found in the array.

4fill in blank

hard

Fill both blanks to create a linear search that returns true if the target is found, false otherwise.

DSA C++

bool linearSearch(int arr[], int n, int target) {
    for (int i = 0; i < [1]; i++) {
        if (arr[i] == [2]) {
            return true;
        }
    }
    return false;
}

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

An

Btarget

Ci

D-1

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong variable for loop limit.

Comparing to the loop index instead of the target.

The loop runs up to n, and compares each element to target.

5fill in blank

hard

Fill all three blanks to create a linear search that returns the index or -1 if not found, using a while loop.

DSA C++

int linearSearch(int arr[], int n, int target) {
    int i = 0;
    while (i [1] n) {
        if (arr[i] == [2]) {
            return [3];
        }
        i++;
    }
    return -1;
}

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

A<

Btarget

Ci

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using <= instead of < in the loop condition causing out-of-bounds access.

Returning the target value instead of the index.

The while loop runs while i < n, compares arr[i] to target, and returns i if found.