48 lines
1.1 KiB
Markdown
48 lines
1.1 KiB
Markdown
# N-Queens
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## What is the N-Queens Problem?
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Imagine you have a chessboard and some queens (the most powerful pieces in chess). The N-Queens problem is like a puzzle where you need to place N queens on an N×N chessboard so that **none of them can attack each other**.
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### What's a Queen in Chess?
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A queen is the strongest piece in chess. She can move:
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- **Horizontally** (left and right)
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- **Vertically** (up and down)
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- **Diagonally** (in any diagonal direction)
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She can move as many squares as she wants in these directions!
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## The Challenge
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Let's say we want to solve the **4-Queens problem** (N=4):
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- We have a 4×4 chessboard (16 squares total)
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- We need to place 4 queens
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- **NO queen can attack any other queen**
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### Example: What Does "Attack" Mean?
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If we put a queen at position (0,0) - that's the top-left corner - she can attack:
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```
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Q . . . ← Queen here attacks all positions marked with X
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X . . .
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X . . .
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X . . .
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```
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```
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Q X X X ← Queen attacks horizontally
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. . . .
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. . . .
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. . . .
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```
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```
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Q . . . ← Queen attacks diagonally
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. X . .
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. . X .
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. . . X
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```
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So we can't put any other queen in any of those X positions! |