Data commit

Task/Nth-root/Swift/nth-root.swift

@@ -0,0 +1,36 @@
+extension FloatingPoint where Self: ExpressibleByFloatLiteral {
+  @inlinable
+  public func power(_ e: Int) -> Self {
+    var res = Self(1)
+
+    for _ in 0..<e {
+      res *= self
+    }
+
+    return res
+  }
+
+  @inlinable
+  public func root(n: Int, epsilon: Self = 2.220446049250313e-16) -> Self {
+    var d = Self(0)
+    var res = Self(1)
+
+    guard self != 0 else {
+      return 0
+    }
+
+    guard n >= 1 else {
+      return .nan
+    }
+
+    repeat {
+      d = (self / res.power(n - 1) - res) / Self(n)
+      res += d
+    } while d >= epsilon * 10 || d <= -epsilon * 10
+
+    return res
+  }
+}
+
+print(81.root(n: 4))
+print(13.root(n: 5))