There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the nth round, you only toggle th…

There is a room with n lights which are turned on initially and 4 buttons on the wall. After performing exactly m unknown operations towards buttons, you need to return how many different kinds of status of the n lights could be. Suppose n lights are…

319. Bulb Switcher My Submissions QuestionEditorial Solution Total Accepted: 15915 Total Submissions: 39596 Difficulty: Medium There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the thi…

There is a room with n lights which are turned on initially and 4 buttons on the wall. After performing exactly m unknown operations towards buttons, you need to return how many different kinds of status of the n lights could be. Suppose n lights are…

[LeetCode]319. Bulb Switcher 解题报告(Python) 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/bulb-switcher/description/ 题目描述: There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the t…

变换灯泡颜色 There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the nth round, you only to…

There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the nth round, you only toggle th…

There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the ith round, you toggle every i…

There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the ith round, you toggle every i…

题目描述: There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the ith round, you toggle e…

There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the ith round, you toggle every i…

题目描述: There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the ith round, you toggle e…

There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the i-th round, you toggle every …

题目: There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the ith round, you toggle eve…

问题描述: There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the nth round, you only tog…

There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the i-th round, you toggle every …

There is a room with n lights which are turned on initially and 4 buttons on the wall. After performing exactly munknown operations towards buttons, you need to return how many different kinds of status of the n lights could be. Suppose n lights are…

初始时有 n 个灯泡关闭. 第 1 轮,你打开所有的灯泡. 第 2 轮,每两个灯泡切换一次开关. 第 3 轮,每三个灯泡切换一次开关(如果关闭,则打开,如果打开则关闭).对于第 i 轮,你每 i 个灯泡切换一次开关. 对于第 n 轮,你只切换最后一个灯泡的开关. 找出 n 轮后有多少个亮着的灯泡.示例:给定 n = 3.状态off表示灯泡关闭,on表示开启.初始时, 灯泡状态 [off, off, off].第一轮后, 灯泡状态 [on, on, on].第二轮后, 灯泡状态 [on, off,…

有n盏关着的灯,第k轮把序号为k倍数的关着的灯打开,开着的灯关闭. class Solution { public: int bulbSwitch(int n) { return (int)sqrt(n*1.0); } };…

初始时有 n 个灯泡关闭. 第 1 轮,你打开所有的灯泡. 第 2 轮,每两个灯泡你关闭一次. 第 3 轮,每三个灯泡切换一次开关(如果关闭则开启,如果开启则关闭).第 i 轮,每 i 个灯泡切换一次开关. 对于第 n 轮,你只切换最后一个灯泡的开关. 找出 n 轮后有多少个亮着的灯泡. 示例: 输入: 3 输出: 1 解释: 初始时, 灯泡状态 [关闭, 关闭, 关闭]. 第一轮后, 灯泡状态 [开启, 开启, 开启]. 第二轮后, 灯泡状态 [开启, 关闭, 开启]. 第三轮后, 灯泡状态…

智商压制的一道题 这个题有个数学定理: 一般数(非完全平方数)的因子有偶数个 完全平凡数的因子有奇数个 开开关的时候,第i个灯每到它的因子一轮的时候就会拨动一下,也就是每个灯拨动的次数是它的因子数 而拨动偶数次是关,拨动奇数次是开 现在就是求哪些数的因子有奇数个,也就是求n以内的完全平凡数 这里又有一个定理: n以内的完全平方数个数是sprt(n) 所以代码很简单 public int bulbSwitch(int n) { return (int)Math.sqrt(n); }…

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 日期 题目地址:https://leetcode.com/problems/bulb-switcher-ii/description/ 题目描述 There is a room with n lights which are turned on initially and 4 buttons on the wall. After performing…

终于将LeetCode的免费题刷完了,真是漫长的第一遍啊,估计很多题都忘的差不多了,这次开个题目汇总贴,并附上每道题目的解题连接,方便之后查阅吧~ 477 Total Hamming Distance 44.10% Meidum 475 Heaters  30.20% Easy 474 Ones and Zeroes  34.90% Meidum 473 Matchsticks to Square  31.80% Medium 472 Concatenated Words 29.20% Hard…

Array 448.找出数组中所有消失的数 要求:整型数组取值为 1 ≤ a[i] ≤ n,n是数组大小,一些元素重复出现,找出[1,n]中没出现的数,实现时时间复杂度为O(n),并不占额外空间 思路1:(discuss)用数组下标标记未出现的数,如出现4就把a[3]的数变成负数,当查找时判断a的正负就能获取下标 tips:注意数组溢出 public List<Integer> findDisappearedNumbers(int[] nums) { List<Integer> d…

463. Island Perimeterhttps://leetcode.com/problems/island-perimeter/就是逐一遍历所有的cell,用分离的cell总的的边数减去重叠的边的数目即可.在查找重叠的边的数目的时候有一点小技巧,就是沿着其中两个方向就好,这种题目都有类似的规律,就是可以沿着上三角或者下三角形的方向来做.一刷一次ac,但是还没开始注意codestyle的问题,需要再刷一遍. class Solution { public: int islandPerime…

Bulb Switcher 灯泡开关 思路:除了平方数以外,其他所有位置的灯泡最终都被开关了偶数次,因此最终都为0.问题等价于求1~n中平方数的个数. public class Solution { public int bulbSwitch(int n) { return (int)Math.sqrt(n); } } Count Primes 质数计数 思路1:暴力法.其中判断每一个数n是不是质数需要验证是否任何小于n的数都不能整除n,这一步是O(n).因此整体复杂度是O(n^2). 思路2:…

Problem Reason Reference Moving ZeroesSort Colors Corner cases   Shortest Word Distance Thought: 2 ptr chasing   Merge 2 sorted ListsRemove Linked List Elem Corner cases   Power of Four Thought: fun bit ops   Pow(x, n) int overflow   Rectangle Area T…

Bulb Switcher There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the ith round, you…

刷题备忘录,for bug-free leetcode 396. Rotate Function 题意: Given an array of integers A and let n to be its length. Assume Bk to be an array obtained by rotating the array A k positions clock-wise, we define a "rotation function" F on A as follow: F(k…

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