Data commit

Task/Partition-function-P/Swift/partition-function-p.swift

@@ -0,0 +1,44 @@
+import BigInt
+
+func partitions(n: Int) -> BigInt {
+  var p = [BigInt(1)]
+
+  for i in 1...n {
+    var num = BigInt(0)
+    var k = 1
+
+    while true {
+      var j = (k * (3 * k - 1)) / 2
+
+      if j > i {
+        break
+      }
+
+      if k & 1 == 1 {
+        num += p[i - j]
+      } else {
+        num -= p[i - j]
+      }
+
+      j += k
+
+      if j > i {
+        break
+      }
+
+      if k & 1 == 1 {
+        num += p[i - j]
+      } else {
+        num -= p[i - j]
+      }
+
+      k += 1
+    }
+
+    p.append(num)
+  }
+
+  return p[n]
+}
+
+print("partitions(6666) = \(partitions(n: 6666))")