Why Binary Search and What Sorted Order Gives You in DSA Go - Test Your Knowledge

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find the middle index in binary search.

DSA Go

mid := (low + [1]) / 2

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Alow

Bhigh

Cmid

Dlen(arr)

Attempts:

3 left

💡 Hint

Common Mistakes

Using low twice instead of high

Using length of array directly

In binary search, the middle index is calculated by adding low and high indices and dividing by 2.

2fill in blank

medium

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

DSA Go

if target > arr[mid] {
    [1] = mid + 1
}

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Alow

Bhigh

Cmid

Dtarget

Attempts:

3 left

💡 Hint

Common Mistakes

Updating high instead of low

Not adding 1 to mid

If 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 run binary search.

DSA Go

for low [1] high {
    mid := (low + high) / 2
    // rest of code
}

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A<=

B<

C>

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using only less than which misses last element

Using greater than

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 create a map of word lengths for words longer than 3 characters.

DSA Go

lengths := map[string]int{}
for _, word := range words {
    if len(word) [1] 3 {
        lengths[word] = [2]
    }
}

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A>

Blen(word)

C<

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using less than instead of greater than

Storing word instead of length

We check if word length is greater than 3, then store the length in the map.

5fill in blank

hard

Fill all three blanks to create a filtered map with uppercase keys and values greater than 0.

DSA Go

filtered := map[string]int{}
for k, v := range data {
    if v [1] 0 {
        filtered[[2]] = v
    }
}

// Convert keys to uppercase
for k := range filtered {
    newKey := [3]
    filtered[newKey] = filtered[k]
    delete(filtered, k)
}

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A>

Bk

Cstrings.ToUpper(k)

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>'

Using value instead of key for map assignment

Not converting key to uppercase

We filter values greater than 0, keep original keys, then convert keys to uppercase.