Quick Sort Algorithm in DSA Go - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to swap two elements in the array.

DSA Go

arr[[1]], arr[j] = arr[j], arr[[1]]

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Aj

Bpivot

Clow

Di

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping with the pivot index instead of i.

Using j twice in the swap.

Swapping elements at positions i and j is needed to reorder elements around the pivot.

2fill in blank

medium

Complete the code to choose the pivot element for partitioning.

DSA Go

pivot := arr[[1]]

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Alow

Bhigh

Cmid

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing the pivot as low or mid index incorrectly.

Using a fixed index like 0 regardless of segment.

The pivot is chosen as the element at the high index for partitioning.

3fill in blank

hard

Fix the error in the partition loop condition.

DSA Go

for j := low; j [1] high; j++ {

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A<

B<=

C>=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using <= causes the pivot to be included in the loop.

Using > or >= causes the loop to never run.

The loop runs from low up to but not including high, so j < high is correct.

4fill in blank

hard

Fill both blanks to complete the recursive quicksort calls.

DSA Go

quickSort(arr, [1], pi-1)
quickSort(arr, pi+1, [2])

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Alow

Bhigh

Cpi

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using pi instead of pi-1 or pi+1 causes infinite recursion.

Using 0 instead of high for right side.

The recursive calls sort the left part from low to pi-1 and right part from pi+1 to high.

5fill in blank

hard

Fill all three blanks to complete the partition function return and variable initialization.

DSA Go

func partition(arr []int, [1] int, [2] int) int {
    pivot := arr[[3]]
    i := [1] - 1
    for j := [1]; j < [2]; j++ {
        if arr[j] < pivot {
            i++
            arr[i], arr[j] = arr[j], arr[i]
        }
    }
    arr[i+1], arr[[2]] = arr[[2]], arr[i+1]
    return i + 1
}

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

Alow

Bhigh

Dpivot

Attempts:

3 left

💡 Hint

Common Mistakes

Using pivot as parameter name instead of low or high.

Choosing pivot as arr[low] instead of arr[high].

Partition uses low and high as parameters; pivot is arr[high].