Given the output of the check function is 1 for candidate value 2 on arrays A and B, which of the following input arrays could produce this result?

hard🔄 Reverse Engineer Q9 of Q15

Greedy Algorithms - Minimum Domino Rotations

AA = [2,1,2,2], B = [2,2,1,2]

BA = [1,1,1,1], B = [2,2,2,2]

CA = [2,2,2,2], B = [1,1,1,1]

DA = [2,3,2,4], B = [2,2,2,2]

Step-by-Step Solution

Solution:

Step 1: Analyze rotations for candidate 2
Count rotations needed on top and bottom for each option.
Step 2: Calculate rotations for A = [2,1,2,2], B = [2,2,1,2]
Rotations on top: position 1 (A[1]=1 != 2) -> 1 rotation; rotations on bottom: position 2 (B[2]=1 != 2) -> 1 rotation; minimum is 1.
Step 3: Verify other options
Options A and B require 0 rotations; A = [2,3,2,4], B = [2,2,2,2] contains invalid values beyond 1 to 6.
Final Answer:
Option A -> Option A
Quick Check:
Only A = [2,1,2,2], B = [2,2,1,2] matches output 1 rotations [OK]

Quick Trick: Count mismatches per side to find minimal rotations [OK]

Common Mistakes:

MISTAKES

Trap Explanation:

PITFALL

Interviewer Note:

CONTEXT

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