Leetcode: Max Consecutive Ones II(unsolved locked problem)
Given a binary array, find the maximum number of consecutive 1s in this array if you can flip at most one 0. Example 1:
Input: [1,0,1,1,0]
Output: 4
Explanation: Flip the first zero will get the the maximum number of consecutive 1s.
After flipping, the maximum number of consecutive 1s is 4.
Note: The input array will only contain 0 and 1.
The length of input array is a positive integer and will not exceed 10,000
Follow up:
What if the input numbers come in one by one as an infinite stream? In other words, you can't store all numbers coming from the stream as it's too large to hold in memory. Could you solve it efficiently?
未研究:
The idea is to keep a window [l, h] that contains at most k zero
The following solution does not handle follow-up, because nums[l] will need to access previous input streamTime: O(n) Space: O(1)
public int findMaxConsecutiveOnes(int[] nums) {
int max = 0, zero = 0, k = 1; // flip at most k zero
for (int l = 0, h = 0; h < nums.length; h++) {
if (nums[h] == 0)
zero++;
while (zero > k)
if (nums[l++] == 0)
zero--;
max = Math.max(max, h - l + 1);
}
return max;
}
Now let's deal with follow-up, we need to store up to k indexes of zero within the window [l, h] so that we know where to move lnext when the window contains more than k zero. If the input stream is infinite, then the output could be extremely large because there could be super long consecutive ones. In that case we can use BigInteger for all indexes. For simplicity, here we will use intTime: O(n) Space: O(k)
public int findMaxConsecutiveOnes(int[] nums) {
int max = 0, k = 1; // flip at most k zero
Queue<Integer> zeroIndex = new LinkedList<>();
for (int l = 0, h = 0; h < nums.length; h++) {
if (nums[h] == 0)
zeroIndex.offer(h);
if (zeroIndex.size() > k)
l = zeroIndex.poll() + 1;
max = Math.max(max, h - l + 1);
}
return max;
}
Note that setting k = 0 will give a solution to the earlier version Max Consecutive Ones
For k = 1 we can apply the same idea to simplify the solution. Here q stores the index of zero within the window [l, h] so its role is similar to Queue in the above solution
public int findMaxConsecutiveOnes(int[] nums) {
int max = 0, q = -1;
for (int l = 0, h = 0; h < nums.length; h++) {
if (nums[h] == 0) {
l = q + 1;
q = h;
}
max = Math.max(max, h - l + 1);
}
return max;
}
Leetcode: Max Consecutive Ones II(unsolved locked problem)的更多相关文章
- [LeetCode] Max Consecutive Ones II 最大连续1的个数之二
Given a binary array, find the maximum number of consecutive 1s in this array if you can flip at mos ...
- LeetCode Max Consecutive Ones II
原题链接在这里:https://leetcode.com/problems/max-consecutive-ones-ii/ 题目: Given a binary array, find the ma ...
- LeetCode——Max Consecutive Ones
LeetCode--Max Consecutive Ones Question Given a binary array, find the maximum number of consecutive ...
- 【LeetCode】487. Max Consecutive Ones II 解题报告 (C++)
作者: 负雪明烛 id: fuxuemingzhu 个人博客:http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 动态规划 日期 题目地址:https://leetco ...
- Leetcode: The Maze(Unsolved locked problem)
There is a ball in a maze with empty spaces and walls. The ball can go through empty spaces by rolli ...
- [LeetCode] Max Consecutive Ones 最大连续1的个数
Given a binary array, find the maximum number of consecutive 1s in this array. Example 1: Input: [1, ...
- 487. Max Consecutive Ones II
Given a binary array, find the maximum number of consecutive 1s in this array if you can flip at mos ...
- LeetCode: Max Consecutive Ones
这题最关键的是处理最开始连续1和最后连续1的方式,想到list一般在最前面加个node的处理方式,在最前面和最后面加0即可以很好地处理了 public class Solution { public ...
- LeetCode 1004. Max Consecutive Ones III
原题链接在这里:https://leetcode.com/problems/max-consecutive-ones-iii/ 题目: Given an array A of 0s and 1s, w ...
随机推荐
- 使用Type.MakeGenericType,反射构造泛型类型
有时我们会有通过反射来动态构造泛型类型的需求,该如何实现呢?举个栗子,比如我们常常定义的泛型委托Func<in T, out TResult>,当T或TResult的类型需要根据程序上下文 ...
- Android 常用知识点
1.Kotlin 将字节大小转换为KB,MB,GB 并保留两位小数 fun getFileSize(size: Long): String { var GB = 1024 * 1024 * 1024 ...
- Beta(5/7)
鐵鍋燉腯鱻 项目:小鱼记账 团队成员 项目燃尽图 冲刺情况描述 站立式会议照片 各成员情况 团队成员 学号 姓名 git地址 博客地址 031602240 许郁杨 (组长) https://githu ...
- Django表单字段汇总
Field.clean(value)[source] 虽然表单字段的Field类主要使用在Form类中,但也可以直接实例化它们来使用,以便更好地了解它们是如何工作的.每个Field的实例都有一个cle ...
- java 多态 向上 向下转型
向上转型 将子类对象当作父类对象 子类对象------>父类对象 先实例化子类 父类 父类对象 = 子类实例 package test2; class Father{ public vo ...
- Python退火算法在高次方程的应用
一,简介 退火算法不言而喻,就是钢铁在淬炼过程中失温而成稳定态时的过程,热力学上温度(内能)越高原子态越不稳定,而温度有一个向低温区辐射降温的物理过程,当物质内能不再降低时候该物质原子态逐渐成为稳定有 ...
- Lesnoe Ozero 2017. BSUIR Open 2017
A. Tree Orientation 树形DP,$f[i][j][k]$表示$i$的子树中有$j$个汇点,$i$往父亲的树边方向为$k$的方案数. 转移则需要另一个DP:$g[i][j][k]$表示 ...
- python统计字词练习
方法一: import operator from nltk.corpus import stopwords stop_words = stopwords.words('English')#目的是去除 ...
- Node.js_密码明文_密文_加密库_sha1
加密库 sha1 加密模块,能够将指定 明文 加密成一个长度相等的 密文 let pwd = 'qwe123456'; const secret = sha1(pwd); 同样的明文,加密得到同样的密 ...
- [LeetCode] Minimum Swaps To Make Sequences Increasing 使得序列递增的最小交换
We have two integer sequences A and B of the same non-zero length. We are allowed to swap elements A ...