Add tasks for all the new languages

Task/Spiral-matrix/Nim/spiral-matrix.nim

@@ -0,0 +1,43 @@
+import strutils
+
+type Pos = tuple[x, y: int]
+
+proc newSeqWith[T](len: int, init: T): seq[T] =
+  result = newSeq[T] len
+  for i in 0 .. <len:
+    result[i] = init
+
+proc `^`*(base: int, exp: int): int =
+  var (base, exp) = (base, exp)
+  result = 1
+
+  while exp != 0:
+    if (exp and 1) != 0:
+      result *= base
+    exp = exp shr 1
+    base *= base
+
+proc `$`(m: seq[seq[int]]): string =
+  result = ""
+  for r in m:
+    for c in r:
+      result.add align($c, 2) & " "
+    result.add "\n"
+
+proc spiral(n): auto =
+  result = newSeqWith(n, newSeqWith[int](n, -1))
+  var dx = 1
+  var dy, x, y = 0
+  for i in 0 .. <(n^2):
+    result[y][x] = i
+    let (nx, ny) = (x+dx, y+dy)
+    if nx in 0 .. <n and ny in 0 .. <n and result[ny][nx] == -1:
+      x = nx
+      y = ny
+    else:
+      swap dx, dy
+      dx = -dx
+      x = x + dx
+      y = y + dy
+
+echo spiral(5)