DSA · Theory

b)LR Rotation

Theory

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Zara only reaches for b)LR Rotation when Zara walking through bLR Rotation has to stay correct in lab hour.

Keep b)LR Rotation small. Zara should finish Zara walking through bLR Rotation in a few lines, not a 40-line dump.

Skip b)LR Rotation and only reciting the name of bLR Rotation shows up in lab hour.

Use b)LR Rotation when Zara walking through bLR Rotation must stay clear. If a simpler DSA step works, use that instead.

Don’t do this with b)LR Rotation — only reciting the name of bLR Rotation. Interviewers spot it in ten seconds.

b)LR Rotation is not a lonely heading. Zara ties it to Zara walking through bLR Rotation.

Close b)LR Rotation with: “If I skip it, Zara walking through bLR Rotation goes wrong like this: only reciting the name of bLR Rotation.”

Exam tip

Board: Zara walking through bLR Rotation. Dry-run b)LR Rotation. Name the trap: only reciting the name of bLR Rotation.

# b)LR Rotation
data = [4, 1, 3]
print("start", data)
if data[0] > data[1]:
    data[0], data[1] = data[1], data[0]
print("after one step", data)

b)LR Rotation: dry-run [4, 1, 3]. Say the list after one step.

Defb)LR Rotation — Zara uses it for Zara walking through bLR Rotation in lab hour.
Ruleb)LR Rotation → one bLR Rotation step Zara can write from memory.
Rememberb)LR Rotation + Big-O (lab hour).
Useb)LR Rotation in lab hour (Zara walking through bLR Rotation).
Trapb)LR Rotation — only reciting the name of bLR Rotation.
Exb)LR Rotation → Zara walking through bLR Rotation.