all tasks

Task/Spiral-matrix/Visual-Basic/spiral-matrix-1.vb

@@ -0,0 +1,58 @@
+Option Explicit
+
+Sub Main()
+    print2dArray getSpiralArray(5)
+End Sub
+
+Function getSpiralArray(dimension As Integer) As Integer()
+    ReDim spiralArray(dimension - 1, dimension - 1) As Integer
+
+    Dim numConcentricSquares As Integer
+    numConcentricSquares = dimension \ 2
+    If (dimension Mod 2) Then numConcentricSquares = numConcentricSquares + 1
+
+
+    Dim j As Integer, sideLen As Integer, currNum As Integer
+    sideLen = dimension
+
+    Dim i As Integer
+    For i = 0 To numConcentricSquares - 1
+        ' do top side
+        For j = 0 To sideLen - 1
+            spiralArray(i, i + j) = currNum
+            currNum = currNum + 1
+        Next
+
+        ' do right side
+        For j = 1 To sideLen - 1
+            spiralArray(i + j, dimension - 1 - i) = currNum
+            currNum = currNum + 1
+        Next
+
+        ' do bottom side
+        For j = sideLen - 2 To 0 Step -1
+            spiralArray(dimension - 1 - i, i + j) = currNum
+            currNum = currNum + 1
+        Next
+
+        ' do left side
+        For j = sideLen - 2 To 1 Step -1
+            spiralArray(i + j, i) = currNum
+            currNum = currNum + 1
+        Next
+
+        sideLen = sideLen - 2
+    Next
+
+    getSpiralArray = spiralArray()
+End Function
+
+Sub print2dArray(arr() As Integer)
+    Dim row As Integer, col As Integer
+    For row = 0 To UBound(arr, 1)
+        For col = 0 To UBound(arr, 2) - 1
+            Debug.Print arr(row, col),
+        Next
+        Debug.Print arr(row, UBound(arr, 2))
+    Next
+End Sub

Task/Spiral-matrix/Visual-Basic/spiral-matrix-2.vb

@@ -0,0 +1,51 @@
+Sub spiral()
+    Dim n As Integer, a As Integer, b As Integer
+    Dim numCsquares As Integer, sideLen As Integer, currNum As Integer
+    Dim j As Integer, i As Integer
+    Dim j1 As Integer, j2 As Integer, j3 As Integer
+
+    n = 5
+
+    Dim spiralArr(9, 9) As Integer
+    numCsquares = CInt(Application.WorksheetFunction.Ceiling(n / 2, 1))
+    sideLen = n
+    currNum = 0
+    For i = 0 To numCsquares - 1
+        'do top side
+        For j = 0 To sideLen - 1
+            currNum = currNum + 1
+            spiralArr(i, i + j) = currNum
+        Next j
+
+        'do right side
+        For j1 = 1 To sideLen - 1
+            currNum = currNum + 1
+            spiralArr(i + j1, n - 1 - i) = currNum
+        Next j1
+
+        'do bottom side
+        j2 = sideLen - 2
+        Do While j2 > -1
+            currNum = currNum + 1
+            spiralArr(n - 1 - i, i + j2) = currNum
+            j2 = j2 - 1
+        Loop
+
+        'do left side
+        j3 = sideLen - 2
+        Do While j3 > 0
+            currNum = currNum + 1
+            spiralArr(i + j3, i) = currNum
+            j3 = j3 - 1
+        Loop
+
+        sideLen = sideLen - 2
+    Next i
+
+    For a = 0 To n - 1
+        For b = 0 To n - 1
+        Cells(a + 1, b + 1).Select
+            ActiveCell.Value = spiralArr(a, b)
+        Next b
+    Next a
+End Sub

Task/Spiral-matrix/Visual-Basic/spiral-matrix-3.vb

@@ -0,0 +1,68 @@
+Sub spiral(n As Integer)
+  Const FREE = -9        'negative number indicates unoccupied cell
+  Dim A() As Integer
+  Dim rowdelta(3) As Integer
+  Dim coldelta(3) As Integer
+
+  'initialize A to a matrix with an extra "border" of occupied cells
+  'this avoids having to test if we've reached the edge of the matrix
+
+  ReDim A(0 To n + 1, 0 To n + 1)
+
+  'Since A is initialized with zeros, setting A(1 to n,1 to n) to "FREE"
+  'leaves a "border" around it occupied with zeroes
+
+  For i = 1 To n: For j = 1 To n: A(i, j) = FREE: Next: Next
+
+  'set amount to move in directions "right", "down", "left", "up"
+
+  rowdelta(0) = 0: coldelta(0) = 1
+  rowdelta(1) = 1: coldelta(1) = 0
+  rowdelta(2) = 0: coldelta(2) = -1
+  rowdelta(3) = -1: coldelta(3) = 0
+
+  curnum = 0
+
+  'set current cell position
+  col = 1
+  row = 1
+
+  'set current direction
+  theDir = 0  'theDir = 1 will fill the matrix counterclockwise
+
+  'ok will be true as long as there is a free cell left
+  ok = True
+
+  Do While ok
+
+     'occupy current FREE cell and increase curnum
+      A(row, col) = curnum
+      curnum = curnum + 1
+
+      'check if next cell in current direction is free
+      'if not, try another direction in clockwise fashion
+      'if all directions lead to occupied cells then we are finished!
+
+      ok = False
+      For i = 0 To 3
+        newdir = (theDir + i) Mod 4
+        If A(row + rowdelta(newdir), col + coldelta(newdir)) = FREE Then
+          'yes, move to it and change direction if necessary
+          theDir = newdir
+          row = row + rowdelta(theDir)
+          col = col + coldelta(theDir)
+          ok = True
+          Exit For
+        End If
+      Next i
+  Loop
+
+  'print result
+  For i = 1 To n
+    For j = 1 To n
+      Debug.Print A(i, j),
+    Next
+    Debug.Print
+  Next
+
+End Sub