1. Initial gap
Comb Sort starts with a wide gap instead of adjacent pairs.
let gap = arr.lengthTyporithm · medium
Comb Sort
▷ Interactive algorithm labcomb-sortsortinggapbubble-sortquadratic-time
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Step 1 of 8 · intro card
Learn Comb Sort
Sorting Algorithms
Comb Sort improves Bubble Sort by comparing values at a shrinking gap before finishing with adjacent swaps.
Bubble Sort only swaps adjacent values, so distant small values move slowly.
Comb Sort starts with a large gap so badly misplaced values can jump farther.
The gap shrinks by a factor until it reaches 1.
When gap is 1, the algorithm behaves like Bubble Sort with an early-exit flag.
It is usually faster than Bubble Sort but still has quadratic worst-case behavior.
Preparing algorithm lab…
01
Start with gap = arr.length.
02
Shrink gap by about 1.3.
03
Compare i with i + gap.
04
Finish when gap is 1 and no swaps occur.
05
Not stable because distant swaps can cross equal values.
function combSort(arr) {
let gap = arr.length;
let swapped = true;
while (gap > 1 || swapped) {
gap = Math.max(1, Math.floor(gap / 1.3));
swapped = false;
for (let i = 0; i + gap < arr.length; i++) {
if (arr[i] > arr[i + gap]) {
[arr[i], arr[i + gap]] = [arr[i + gap], arr[i]];
swapped = true;
}
}
}
return arr;
}Read the implementation
Connect each part of the code to the concept before you type.
2. Swap flag
The loop continues until gap is 1 and no swaps happen.
let swapped = true3. Loop condition
Keep going while gaps remain or the last adjacent pass still swapped.
while (gap > 1 || swapped)4. Shrink gap
The gap shrinks by about 1.3 but never below 1.
gap = Math.max(1, Math.floor(gap / 1.3))5. Gapped scan
Only compare pairs where i + gap is still in bounds.
for (let i = 0; i + gap < arr.length; i++)6. Gapped comparison
Compare values separated by the current gap.
arr[i] > arr[i + gap]7. Gapped swap
Swap distant out-of-order values.
[arr[i], arr[i + gap]] = [arr[i + gap], arr[i]]A complete learning loop
01
Understand
Read the concept map and follow the code breakdown.
02
Reconstruct
Type the implementation, repair mistakes and work through every recall exercise.
03
Verify
Use the final check without hints; revisit weak concepts in short practice sessions.