Time: 124 ms (12.47%), Space: 64 MB (99.06%) - LeetHub

0146-lru-cache/0146-lru-cache.go

@@ -0,0 +1,80 @@
+type Node struct {
+    Prev, Next *Node
+    Key, Value int
+}
+
+func newNode(key, val int) *Node {
+    return &Node{
+        Key: key,
+        Value: val,
+    }
+}
+
+type LRUCache struct {
+    Head, Tail *Node
+    Mp map[int]*Node
+    Capacity int
+}
+
+func newLRUCache(head, tail *Node, cap int) LRUCache {
+	return LRUCache{
+		Head:     head,
+		Tail:     tail,
+		Mp:       make(map[int]*Node),
+		Capacity: cap,
+	}
+}
+
+func (this *LRUCache) remove(node *Node) {
+    delete(this.Mp, node.Key)
+    node.Prev.Next = node.Next
+    node.Next.Prev = node.Prev
+}
+
+func (this *LRUCache) insert(node *Node) {
+    this.Mp[node.Key] = node
+    next := this.Head.Next
+    this.Head.Next = node
+    node.Prev = this.Head
+    next.Prev = node
+    node.Next = next
+}
+
+func Constructor(capacity int) LRUCache {
+    head, tail := newNode(0, 0), newNode(0, 0)
+
+    head.Next = tail
+    tail.Prev = head
+    return newLRUCache(head, tail, capacity)
+}
+
+func (this *LRUCache) Get(key int) int {
+    if n, ok := this.Mp[key]; ok {
+        this.remove(n)
+        this.insert(n)
+        return n.Value
+    }
+
+    return -1
+}
+
+
+func (this *LRUCache) Put(key int, value int)  {
+    if _, ok := this.Mp[key]; ok {
+        this.remove(this.Mp[key])
+    }
+
+    if len(this.Mp) == this.Capacity {
+        this.remove(this.Tail.Prev)
+    }
+
+    this.insert(newNode(key, value))
+}
+
+
+/**
+ * Your LRUCache object will be instantiated and called as such:
+ * obj := Constructor(capacity);
+ * param_1 := obj.Get(key);
+ * obj.Put(key,value);
+ */