Merge pull request #1055 from xiaofei-2020/stack7

添加（0239.滑动窗口最大值.md）：增加typescript版本&修改js版本

problems/0239.滑动窗口最大值.md

@@ -395,30 +395,102 @@ func maxSlidingWindow(nums []int, k int) []int {
 
 Javascript:
 ```javascript
+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {number[]}
+ */
 var maxSlidingWindow = function (nums, k) {
-  // 队列数组（存放的是元素下标，为了取值方便）
-  const q = [];
-  // 结果数组
-  const ans = [];
-  for (let i = 0; i < nums.length; i++) {
-    // 若队列不为空，且当前元素大于等于队尾所存下标的元素，则弹出队尾
-    while (q.length && nums[i] >= nums[q[q.length - 1]]) {
-      q.pop();
+    class MonoQueue {
+        queue;
+        constructor() {
+            this.queue = [];
+        }
+        enqueue(value) {
+            let back = this.queue[this.queue.length - 1];
+            while (back !== undefined && back < value) {
+                this.queue.pop();
+                back = this.queue[this.queue.length - 1];
+            }
+            this.queue.push(value);
+        }
+        dequeue(value) {
+            let front = this.front();
+            if (front === value) {
+                this.queue.shift();
+            }
+        }
+        front() {
+            return this.queue[0];
+        }
     }
-    // 入队当前元素下标
-    q.push(i);
-    // 判断当前最大值（即队首元素）是否在窗口中，若不在便将其出队
-    if (q[0] <= i - k) {
-      q.shift();
+    let helperQueue = new MonoQueue();
+    let i = 0, j = 0;
+    let resArr = [];
+    while (j < k) {
+        helperQueue.enqueue(nums[j++]);
     }
-    // 当达到窗口大小时便开始向结果中添加数据
-    if (i >= k - 1) ans.push(nums[q[0]]);
-  }
-  return ans;
+    resArr.push(helperQueue.front());
+    while (j < nums.length) {
+        helperQueue.enqueue(nums[j]);
+        helperQueue.dequeue(nums[i]);
+        resArr.push(helperQueue.front());
+        i++, j++;
+    }
+    return resArr;
+};
+```
+
+TypeScript：
+
+```typescript
+function maxSlidingWindow(nums: number[], k: number): number[] {
+    /** 单调递减队列 */
+    class MonoQueue {
+        private queue: number[];
+        constructor() {
+            this.queue = [];
+        };
+        /** 入队：value如果大于队尾元素，则将队尾元素删除，直至队尾元素大于value，或者队列为空 */
+        public enqueue(value: number): void {
+            let back: number | undefined = this.queue[this.queue.length - 1];
+            while (back !== undefined && back < value) {
+                this.queue.pop();
+                back = this.queue[this.queue.length - 1];
+            }
+            this.queue.push(value);
+        };
+        /** 出队：只有当队头元素等于value，才出队 */
+        public dequeue(value: number): void {
+            let top: number | undefined = this.top();
+            if (top !== undefined && top === value) {
+                this.queue.shift();
+            }
+        }
+        public top(): number | undefined {
+            return this.queue[0];
+        }
+    }
+    const helperQueue: MonoQueue = new MonoQueue();
+    let i: number = 0,
+        j: number = 0;
+    let resArr: number[] = [];
+    while (j < k) {
+        helperQueue.enqueue(nums[j++]);
+    }
+    resArr.push(helperQueue.top()!);
+    while (j < nums.length) {
+        helperQueue.enqueue(nums[j]);
+        helperQueue.dequeue(nums[i]);
+        resArr.push(helperQueue.top()!);
+        j++, i++;
+    }
+    return resArr;
 };
 ```
 
 Swift:
+
 ```Swift
 /// 双向链表
 class DoublyListNode {