[239. Sliding Window Maximum][Time Limit Exceeded]committed by LeetCo…

…de Extension

239-Sliding-Window-Maximum/solution.java

@@ -0,0 +1,32 @@
+public class Solution {
+    public void addElement(Deque<Integer> dq, int element){
+        while(!dq.isEmpty() && dq.peekLast() <= element){
+            dq.pollLast();
+        }
+        dq.offerLast(element);
+    }
+
+    public void removeElement(Deque<Integer> dq, int element){
+        if(!dq.isEmpty() && dq.peekFirst() == element){
+            dq.pollFirst();
+        }
+    }
+    public int[] maxSlidingWindow(int[] nums, int k) {
+       if (nums == null || k <= 0) {
+			return new int[0];
+		}
+
+       Deque<Integer> dq = new ArrayDeque<Integer>();
+       int length = nums.length;
+       int[] result = new int[length - k +1];
+       for(int i =0; i <k-1; i++){
+           addElement(dq, nums[i]);
+       }
+       for(int j = k-1; j < nums.length; j++){
+           addElement(dq, nums[j]);
+           result[j-k+1] = dq.peekFirst();
+           removeElement(dq, nums[j-k+1]);
+       }
+     return result;  
+    }
+}