ddmin Stepper

ddmin, one test at a time

Delta debugging's minimization algorithm from CIS 5470 slides 59–60. Pick a scenario, then step through every test it runs. Each bar below the change set is one input that was tried: dark cells are changes kept, red marks the changes the failure needs.

0tests run

1iteration

2n (pieces)

0|c|

–log₂ N

Keys: ← → step · ↓ finish iteration · space play · Home / End

Iterations

#	n	\|c\|	tests	outcome

Click a row to jump to it.

The rules (slide 60)

Split c into n pieces Δ₁…Δₙ.
Some Δᵢ fails → c = Δᵢ, n = 2.
Some complement ∇ᵢ = c − Δᵢ fails → c = ∇ᵢ, n = max(n−1, 2).
Nothing fails → n = min(2n, |c|), or stop if n = |c|.

With n = 2 the complements are the two halves again, so they are skipped. A test seen before is answered from the cache and not counted.

change kept removed needed for failure other pieces