feat: add swift solution to lc problem: No.0160 (doocs#721)

No.0160.Intersection of Two Linked Lists

Author: faimin

solution/0100-0199/0160.Intersection of Two Linked Lists/README.md

@@ -228,6 +228,47 @@ function getIntersectionNode(
 }
 ```
 
+### **Swift**
+
+```swift
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public var val: Int
+ *     public var next: ListNode?
+ *     public init(_ val: Int) {
+ *         self.val = val
+ *         self.next = nil
+ *     }
+ * }
+ */
+
+class Solution {
+    func getIntersectionNode(_ headA: ListNode?, _ headB: ListNode?) -> ListNode? {
+
+        guard let _ = headA, let _ = headB else {
+            return nil
+        }
+
+        var nodeA = headA
+        var nodeB = headB
+
+        while nodeA != nodeB {
+            nodeA = nodeA != nil ? nodeA?.next : headB
+            nodeB = nodeB != nil ? nodeB?.next : headA
+        }
+
+        return nodeA
+    }
+}
+
+extension ListNode: Equatable {
+    public static func ==(lhs: ListNode, rhs: ListNode) -> Bool {
+        return ObjectIdentifier(lhs) == ObjectIdentifier(rhs)
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0100-0199/0160.Intersection of Two Linked Lists/README_EN.md

@@ -214,6 +214,47 @@ function getIntersectionNode(
 }
 ```
 
+### **Swift**
+
+```swift
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public var val: Int
+ *     public var next: ListNode?
+ *     public init(_ val: Int) {
+ *         self.val = val
+ *         self.next = nil
+ *     }
+ * }
+ */
+
+class Solution {
+    func getIntersectionNode(_ headA: ListNode?, _ headB: ListNode?) -> ListNode? {
+
+        guard let _ = headA, let _ = headB else {
+            return nil
+        }
+
+        var nodeA = headA
+        var nodeB = headB
+
+        while nodeA != nodeB {
+            nodeA = nodeA != nil ? nodeA?.next : headB
+            nodeB = nodeB != nil ? nodeB?.next : headA
+        }
+
+        return nodeA
+    }
+}
+
+extension ListNode: Equatable {
+    public static func ==(lhs: ListNode, rhs: ListNode) -> Bool {
+        return ObjectIdentifier(lhs) == ObjectIdentifier(rhs)
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0100-0199/0160.Intersection of Two Linked Lists/Solution.swift

@@ -0,0 +1,35 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public var val: Int
+ *     public var next: ListNode?
+ *     public init(_ val: Int) {
+ *         self.val = val
+ *         self.next = nil
+ *     }
+ * }
+ */
+
+class Solution {
+    func getIntersectionNode(_ headA: ListNode?, _ headB: ListNode?) -> ListNode? {
+        guard let _ = headA, let _ = headB else {
+            return nil
+        }
+
+        var nodeA = headA
+        var nodeB = headB
+
+        while nodeA != nodeB {
+            nodeA = nodeA != nil ? nodeA?.next : headB
+            nodeB = nodeB != nil ? nodeB?.next : headA
+        }
+
+        return nodeA
+    }
+}
+
+extension ListNode: Equatable {
+    public static func == (lhs: ListNode, rhs: ListNode) -> Bool {
+        return ObjectIdentifier(lhs) == ObjectIdentifier(rhs)
+    }
+}