Data commit

Task/Sudoku/FreeBASIC/sudoku.basic

@@ -0,0 +1,87 @@
+Dim Shared As Integer cuadricula(9, 9), cuadriculaResuelta(9, 9)
+
+Function isSafe(i As Integer, j As Integer, n As Integer) As Boolean
+    Dim As Integer iMin, jMin, f, c
+
+    If cuadricula(i, j) <> 0 Then Return (cuadricula(i, j) = n)
+
+    'cuadricula(i, j) es una celda vacía. Compruebe si n está OK
+    'primero revisa la fila i
+    For f = 1 To 9
+        If cuadricula(i, f) = n Then Return False
+    Next f
+
+    'ahora comprueba la columna j
+    For c = 1 To 9
+        If cuadricula(c, j) = n Then Return False
+    Next c
+
+    'finalmente, compruebe el subcuadrado de 3x3 que contiene cuadricula(i,j)
+    iMin = 1 + 3 * Int((i - 1) / 3)
+    jMin = 1 + 3 * Int((j - 1) / 3)
+    For c = iMin To iMin + 2
+        For f = jMin To jMin + 2
+            If cuadricula(c, f) = n Then Return False
+        Next f
+    Next c
+
+    'todas las pruebas estuvieron OK
+    Return True
+End Function
+
+Sub Resolver(i As Integer, j As Integer)
+    Dim As Integer f, c, n, temp
+    If i > 9 Then
+        'salir con cuadriculaResuelta = cuadricula
+        For c = 1 To 9
+            For f = 1 To 9
+                cuadriculaResuelta(c, f) = cuadricula(c, f)
+            Next f
+        Next c
+        Exit Sub
+    End If
+    For n = 1 To 9
+        If isSafe(i, j, n) Then
+            temp = cuadricula(i, j)
+            cuadricula(i, j) = n
+            If j = 9 Then
+                Resolver i + 1, 1
+            Else
+                Resolver i, j + 1
+            End If
+            cuadricula(i, j) = temp
+        End If
+    Next n
+End Sub
+
+Dim As String s(9)
+'inicializar la cuadrícula usando 9 cadenas, una por fila
+s(1) = "001005070"
+s(2) = "920600000"
+s(3) = "008000600"
+s(4) = "090020401"
+s(5) = "000000000"
+s(6) = "304080090"
+s(7) = "007000300"
+s(8) = "000007069"
+s(9) = "010800700"
+
+Dim As Integer i, j
+For i = 1 To 9
+    For j = 1 To 9
+        cuadricula(i, j) = Int(Val(Mid(s(i), j, 1)))
+    Next j
+Next i
+
+Resolver 1, 1
+Print "Solucion:"
+Color 12: Print "---------+---------+---------"
+For i = 1 To 9
+    For j = 1 To 9
+        Color 7: Print cuadriculaResuelta(i, j); " ";
+        Color 12
+        If (j Mod 3 = 0) And (j <> 9) Then Color 12: Print "|";
+    Next j
+    If (i Mod 3 = 0) Then Print !"\n---------+---------+---------" Else Print
+Next i
+Sleep