标签：
Sliding Window Maximum
Given an array nums, there is a sliding window of size k which is moving from the very left of the array to the very right. You can only see the k numbers in the window. Each time the sliding window moves right by one position.
For example,
Given nums = [1,3,-1,-3,5,3,6,7], and k = 3.
Window position Max --------------- ----- [1 3 -1] -3 5 3 6 7 3 1 [3 -1 -3] 5 3 6 7 3 1 3 [-1 -3 5] 3 6 7 5 1 3 -1 [-3 5 3] 6 7 5 1 3 -1 -3 [5 3 6] 7 6 1 3 -1 -3 5 [3 6 7] 7
Therefore, return the max sliding window as [3,3,5,5,6,7].
Note:
You may assume k is always valid, ie: 1 ≤ k ≤ input array‘s size for non-empty array.
Follow up:
Could you solve it in linear time?
Hint:
class MonoQue { public: deque<pair<int, int> > q; int maxV() { return q.front().first; } void push(int n) { int count = 0; while(!q.empty() && q.back().first < n) { count += (q.back().second + 1); q.pop_back(); } q.push_back(make_pair(n, count)); } void pop() { if(q.front().second > 0) q.front().second --; else q.pop_front(); } }; class Solution { public: vector<int> maxSlidingWindow(vector<int>& nums, int k) { vector<int> ret; if(k == 0) return ret; MonoQue mq; for(int i = 0; i < k; i ++) mq.push(nums[i]); for(int i = k; i < nums.size(); i ++) { ret.push_back(mq.maxV()); mq.pop(); mq.push(nums[i]); } ret.push_back(mq.maxV()); return ret; } };
【LeetCode】239. Sliding Window Maximum
标签：
原文地址：http://www.cnblogs.com/ganganloveu/p/4676424.html
