add 138

Author: edboffical

copy-list-with-random-pointer.go

@@ -0,0 +1,15 @@
+package main
+
+// 138 https://leetcode-cn.com/problems/copy-list-with-random-pointer/
+// 哈希 哈希的 key 是旧链表，有指向关系 哈希的 value 是新链表 只是结构
+func copyRandomList(head *Node) *Node {
+	h := map[*Node]*Node{}
+	for p := head; p != nil; p = p.Next {
+		h[p] = &Node{p.Val, nil, nil}
+	}
+	for p := head; p != nil; p = p.Next {
+		h[p].Next = h[p.Next]
+		h[p].Random = h[p.Random]
+	}
+	return h[head]
+}