From 06bba6ca68ec45412bf238007450c73e36e1685f Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Mon, 21 Dec 2020 21:00:42 +0100
Subject: [PATCH] sudoku: constraints: add solved predicate

---
 src/constraints.c | 18 ++++++++++++++++++
 src/constraints.h |  2 ++
 2 files changed, 20 insertions(+)

diff --git a/src/constraints.c b/src/constraints.c
index c2edcc2..8ecb387 100644
--- a/src/constraints.c
+++ b/src/constraints.c
@@ -48,3 +48,21 @@ bool square_violation(const struct sudoku *grid, size_t i, size_t j) {
 
     return false;
 }
+
+bool solved(const struct sudoku *grid) {
+    if (!grid)
+        return false;
+
+    for (size_t i = 0; i < 9; ++i) {
+        for (size_t j = 0; j < 9; ++j) {
+            if (line_violation(grid, i, j))
+                return false;
+            if (column_violation(grid, i, j))
+                return false;
+            if (square_violation(grid, i, j))
+                return false;
+        }
+    }
+
+    return true;
+}
diff --git a/src/constraints.h b/src/constraints.h
index 09e73a0..618448c 100644
--- a/src/constraints.h
+++ b/src/constraints.h
@@ -10,4 +10,6 @@ bool line_violation(const struct sudoku *grid, size_t i, size_t j);
 bool column_violation(const struct sudoku *grid, size_t i, size_t j);
 bool square_violation(const struct sudoku *grid, size_t i, size_t j);
 
+bool solved(const struct sudoku *grid);
+
 #endif /* !CONSTRAINTS_H */