diff --git a/sud.c b/sud.c
index 420d8f1..3d2bb12 100644
--- a/sud.c
+++ b/sud.c
@@ -35,6 +35,18 @@ static void initposs(struct sudoku *sud)
 	}
 }
 
+bool load(struct sudoku *sud, const char *ptr)
+{
+	initposs(sud);
+	for (unsigned i = 0; i < NCELLS; ++i) {
+		if (ptr[i] == '0')
+			continue;
+		if (update(sud, i / NDIGITS, i % NDIGITS, ptr[i] - '1') != OK)
+			return false;
+	}
+	return true;
+}
+
 static void clear(struct sudoku *sud, unsigned r, unsigned c)
 {
 	unsigned tr, tc, val;
diff --git a/sud.h b/sud.h
index 18ceb8a..bdb8971 100644
--- a/sud.h
+++ b/sud.h
@@ -23,6 +23,7 @@
 
 #define SEGLEN 3
 #define NDIGITS (SEGLEN * SEGLEN)
+#define NCELLS (NDIGITS * NDIGITS)
 
 struct cellstate {
 	bool det;
@@ -40,6 +41,12 @@ enum update_res { NOT_ALLOWED, ALREADY_DET, OK };
 
 enum check_res { INCOMPLETE, INCORRECT, SOLVED };
 
+/**
+ * Read `NCELLS` values from the given pointer and load them into the
+ * sudoku.
+ */
+bool load(struct sudoku *sud, const char *ptr);
+
 /**
  * Populate the sudoku with some random values. The proportion of
  * cells that are filled will be approximately `fill_prop`.