How would you combine en passant logic with move history to ensure correct validation in a chess engine?

hard📝 Trade-off Q9 of Q15

LLD - Design — Chess Game

AStore the last move and check if it was a two-step pawn advance adjacent to the capturing pawn

BStore all pawn positions and check if any moved two steps in the last 10 moves

CIgnore move history and allow en passant anytime a pawn is adjacent

DTrack only captures and ignore pawn moves

Step-by-Step Solution

Solution:

Step 1: Understand en passant timing dependency
En passant is only valid immediately after an opponent pawn moves two squares forward.
Step 2: Use move history to validate
Storing the last move allows checking if it was a two-step pawn advance adjacent to the capturing pawn.
Final Answer:
Store the last move and check if it was a two-step pawn advance adjacent to the capturing pawn -> Option A
Quick Check:
En passant validation with move history = A [OK]

Quick Trick: Check only last move for en passant validity [OK]

Common Mistakes:

MISTAKES

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