feat: azl397985856#460

Author: luzhipeng

Diff for: README.en.md

@@ -197,13 +197,15 @@ The data structures mainly includes:
 - [0023.merge-k-sorted-lists](./problems/23.merge-k-sorted-lists.md)
 - [0032.longest-valid-parentheses](./problems/32.longest-valid-parentheses.md) 🆕
 - [0042.trapping-rain-water](./problems/42.trapping-rain-water.md)
-- [0124.binary-tree-maximum-path-sum](./problems/124.binary-tree-maximum-path-sum.md) 🆕
-- [0128.longest-consecutive-sequence](./problems/128.longest-consecutive-sequence.md) 🆕
+- [0124.binary-tree-maximum-path-sum](./problems/124.binary-tree-maximum-path-sum.md)
+- [0128.longest-consecutive-sequence](./problems/128.longest-consecutive-sequence.md)
 - [0145.binary-tree-postorder-traversal](./problems/145.binary-tree-postorder-traversal.md)
 - [0146.lru-cache](./problems/146.lru-cache.md)
 - [0239.sliding-window-maximum](./problems/239.sliding-window-maximum.md)
 - [0295.find-median-from-data-stream](./problems/295.find-median-from-data-stream.md) 🆕
 - [0301.remove-invalid-parentheses](./problems/301.remove-invalid-parentheses.md)
+- [0460.lfu-cache](./problems/460.lfu-cache.md) 🆕
+
 
 
 

Diff for: README.md

@@ -213,16 +213,18 @@ leetcode 题解，记录自己的 leetcode 解题之路。
 - [1031.maximum-sum-of-two-non-overlapping-subarrays](./problems/1031.maximum-sum-of-two-non-overlapping-subarrays.md) 🆕
 
 #### 困难难度
+
 - [0023.merge-k-sorted-lists](./problems/23.merge-k-sorted-lists.md)
 - [0032.longest-valid-parentheses](./problems/32.longest-valid-parentheses.md) 🆕
 - [0042.trapping-rain-water](./problems/42.trapping-rain-water.md)
-- [0124.binary-tree-maximum-path-sum](./problems/124.binary-tree-maximum-path-sum.md) 🆕
-- [0128.longest-consecutive-sequence](./problems/128.longest-consecutive-sequence.md) 🆕
+- [0124.binary-tree-maximum-path-sum](./problems/124.binary-tree-maximum-path-sum.md)
+- [0128.longest-consecutive-sequence](./problems/128.longest-consecutive-sequence.md)
 - [0145.binary-tree-postorder-traversal](./problems/145.binary-tree-postorder-traversal.md)
 - [0146.lru-cache](./problems/146.lru-cache.md)
 - [0239.sliding-window-maximum](./problems/239.sliding-window-maximum.md)
 - [0295.find-median-from-data-stream](./problems/295.find-median-from-data-stream.md) 🆕
 - [0301.remove-invalid-parentheses](./problems/301.remove-invalid-parentheses.md)
+- [0460.lfu-cache](./problems/460.lfu-cache.md) 🆕
 
 ### 数据结构与算法的总结
 

Diff for: daily/answers/460.lfu-cache.js

@@ -0,0 +1,87 @@
+/*
+ * @lc app=leetcode id=460 lang=javascript
+ *
+ * [460] LFU Cache
+ */
+/**
+ * @param {number} capacity
+ */
+var LFUCache = function(capacity) {
+  this.capacity = capacity;
+  this.size = 0;
+  this.cache = {};
+  this.timestamp = 0;
+};
+
+/**
+ * @param {number} key
+ * @return {number}
+ */
+LFUCache.prototype.get = function(key) {
+  const hit = this.cache[key];
+
+  if (hit === void 0) {
+    return -1;
+  }
+  hit.count += 1;
+  hit.timestamp = this.timestamp++;
+
+  return hit.value;
+};
+
+// 时间复杂度O(n)   n其实就是capacity
+LFUCache.prototype.evicted = function() {
+  // evicted lfu
+  let leastCountKey = null;
+  let min = Number.MAX_VALUE;
+
+  for (const k in this.cache) {
+    const item = this.cache[k];
+    if (item.count < min) {
+      leastCountKey = k;
+      min = item.count;
+    } else if (
+      item.count === min &&
+      item.timestamp < this.cache[leastCountKey].timestamp
+    ) {
+      leastCountKey = k;
+      min = item.count;
+    }
+  }
+
+  delete this.cache[leastCountKey];
+  this.size--;
+};
+
+/**
+ * @param {number} key
+ * @param {number} value
+ * @return {void}
+ */
+LFUCache.prototype.put = function(key, value) {
+  if (this.capacity === 0) return;
+  const hit = this.cache[key];
+
+  if (hit === void 0) {
+    if (this.capacity === this.size) {
+      this.evicted();
+    }
+    this.size++;
+    return (this.cache[key] = {
+      value,
+      timestamp: this.timestamp++,
+      count: 1
+    });
+  }
+
+  this.cache[key].value = value;
+  this.cache[key].timestamp = this.timestamp++;
+  return (this.cache[key].count += 1);
+};
+
+/**
+ * Your LFUCache object will be instantiated and called as such:
+ * var obj = new LFUCache(capacity)
+ * var param_1 = obj.get(key)
+ * obj.put(key,value)
+ */