From cd792a0f8a194bcb2f3c8f919b5efa54ee9fa8a8 Mon Sep 17 00:00:00 2001
From: Persson-dev <sim16.prib@gmail.com>
Date: Wed, 29 Jan 2025 15:48:01 +0100
Subject: [PATCH] add diagonal constraint

---
 .../sudoku/constraint/DiagonalConstraint.java | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 app/src/main/java/sudoku/constraint/DiagonalConstraint.java

diff --git a/app/src/main/java/sudoku/constraint/DiagonalConstraint.java b/app/src/main/java/sudoku/constraint/DiagonalConstraint.java
new file mode 100644
index 0000000..63f9ad6
--- /dev/null
+++ b/app/src/main/java/sudoku/constraint/DiagonalConstraint.java
@@ -0,0 +1,24 @@
+package sudoku.constraint;
+
+import sudoku.structure.Sudoku;
+
+public class DiagonalConstraint implements IConstraint {
+
+	@Override
+	public boolean canBePlaced(Sudoku s, int x, int y, int newSymbolIndex) {
+		if (x == y) {
+			for (int i = 0; i < s.getSize(); i++) {
+				if (s.getCell(i, i).getSymbolIndex() == newSymbolIndex)
+				return false;
+			}
+		} else if (s.getSize() - x == y) {
+			for (int i = 0; i < s.getSize(); i++) {
+				if (s.getCell(s.getSize() - i, i).getSymbolIndex() == newSymbolIndex)
+				return false;
+			}
+		}
+		// not in diagonal
+		return true;
+	}
+
+}