64滑动窗口的最大值

 

题目描述

给定一个数组和滑动窗口的大小,找出所有滑动窗口里数值的最大值。例如,如果输入数组{2,3,4,2,6,2,5,1}及滑动窗口的大小3,那么一共存在6个滑动窗口,他们的最大值分别为{4,4,6,6,6,5}; 针对数组{2,3,4,2,6,2,5,1}的滑动窗口有以下6个: {[2,3,4],2,6,2,5,1}, {2,[3,4,2],6,2,5,1}, {2,3,[4,2,6],2,5,1}, {2,3,4,[2,6,2],5,1}, {2,3,4,2,[6,2,5],1}, {2,3,4,2,6,[2,5,1]}


法1:暴力

 1 # -*- coding:utf-8 -*-
 2 class Solution:
 3     def maxInWindows(self, nums, k):
 4         # write code here
 5         if not k or k>len(nums):
 6             return []
 7         maxs = [max(nums[:k])]
 8         for i in range(len(nums)-k):
 9             maxs.append(max(nums[i+1:i+k+1]))
10         return maxs
11  

 

运行时间:30ms
占用内存:5760k


法2:增加判断条件 参考网上

 1 # -*- coding:utf-8 -*-
 2 class Solution:
 3     def maxInWindows(self, nums, k):
 4         # write code here
 5         if not k or k>len(nums):
 6             return []
 7         maxs = [max(nums[:k])]
 8         curmax = maxs[0]
 9         for i in range(len(nums)-k):
10             if curmax==nums[i]:#如果当前最大数字是窗口的首元素,那么下一个窗口的最大元素在后面
11                 curmax = max(nums[i+1:i+k+1])
12             elif curmax<nums[i+k]: #如果新的窗口的首元素大于当前当前窗口最大值,更新curmax
13                 curmax = nums[i+k]
14             maxs.append(curmax)
15         return maxs
16  

 

运行时间:26ms
占用内存:5640k

posted @ 2018-01-18 19:17  乐乐章  阅读(149)  评论(0编辑  收藏  举报