[Solved] You have two arrays representing the top and bottom halves of dominoes.... Which algorithmic approach guarantees an optimal solution with minimal rotations? | Greedy Algorithms

Greedy Algorithms - Minimum Domino Rotations

You have two arrays representing the top and bottom halves of dominoes. You want to make all values in one row uniform by rotating some dominoes. Which algorithmic approach guarantees an optimal solution with minimal rotations?

ADynamic Programming that tries all possible uniform values and stores intermediate results

BGreedy approach checking only the two candidate values from the first domino

CBacktracking to try all rotation combinations exhaustively

DSorting both arrays and then matching values to minimize rotations

Step-by-Step Solution

Step 1: Identify candidate values from the first domino
The only possible uniform values are the top or bottom value of the first domino, since all dominoes must match one of these.
Step 2: Check feasibility and count rotations
For each candidate, verify if all dominoes can be rotated to match it and count minimal rotations needed.
Final Answer:
Option B -> Option B
Quick Check:
Checking only two candidates reduces complexity and guarantees correctness [OK]

Quick Trick: Only two candidates from first domino suffice [OK]

Common Mistakes:

MISTAKES

Trying all numbers 1-6 unnecessarily
Using DP or backtracking wasting time

Trap Explanation:

PITFALL

Candidates often think all six numbers must be checked, but only two candidates matter.

Interviewer Note:

CONTEXT

Tests if candidate recognizes the greedy pattern and pruning in this problem.

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More Greedy Algorithms Quizzes

Which algorithmic approach guarantees an optimal solution with minimal rotations?

Step 1: Identify candidate values from the first domino

Step 2: Check feasibility and count rotations

Final Answer:

Quick Check:

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