add sliding win max

Author: tg123

sliding-window-maximum/README.md

@@ -0,0 +1,52 @@
+public class Solution {
+
+    static class SlidingMaxQueue {
+
+        int[] nums;
+        int k;
+
+        LinkedList<Integer> queue = new LinkedList<>();
+
+        SlidingMaxQueue(int[] nums, int k){
+            this.nums = nums;
+            this.k = k;
+        }
+
+        int max(){
+            return nums[queue.peekFirst()];
+        }
+
+        void add(int i){
+
+            if(i >= nums.length) return;
+
+            // remove invalid index
+            while(!queue.isEmpty() && queue.peekFirst() <= i - k){
+                queue.pollFirst();
+            }
+
+            // remove nums < current;
+            while(!queue.isEmpty() && nums[queue.peekLast()] < nums[i]){
+                queue.pollLast();
+            }
+
+            queue.add(i);
+        }
+    }
+
+    public int[] maxSlidingWindow(int[] nums, int k) {
+
+        int[] T = new int[Math.min(nums.length - k + 1, nums.length)];
+
+        SlidingMaxQueue Q = new SlidingMaxQueue(nums, k);
+
+        Q.add(0);
+
+        for(int i = 1; i <= nums.length; i++){
+            T[Math.max(i - k, 0)] = Q.max();
+            Q.add(i);
+        }
+
+        return T;
+    }
+}

sliding-window-maximum/Solution.java

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+---
+layout: solution
+title: Sliding Window Maximum
+date: 2015-07-26 16:53:20+08:00
+leetcode_id: 239
+---
+{% include_relative README.md %}