[LeetCode]779. K-th Symbol in Grammar 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/k-th-symbol-in-grammar/description/ 题目描述: On the first row, we write a 0. Now in every subsequent row, we lo…

LeetCode 25 k组一个翻转链表 TITLE 示例 1: 输入:head = [1,2,3,4,5], k = 2 输出:[2,1,4,3,5] 示例 2: 输入:head = [1,2,3,4,5], k = 3 输出:[3,2,1,4,5] 示例 3: 输入:head = [1,2,3,4,5], k = 1 输出:[1,2,3,4,5] 示例 4: 输入:head = [1], k = 1 输出:[1] (PS:还是加上title吧不然太难受了) 前言:LeetCode难度hard…

On the first row, we write a 0. Now in every subsequent row, we look at the previous row and replace each occurrence of 0 with 01, and each occurrence of 1 with 10. Given row N and index K, return the K-th indexed symbol in row N. (The values of K ar…

On the first row, we write a 0. Now in every subsequent row, we look at the previous row and replace each occurrence of 0 with 01, and each occurrence of 1 with 10. Given row N and index K, return the K-th indexed symbol in row N. (The values of K ar…

779. 第K个语法符号 在第一行我们写上一个 0.接下来的每一行,将前一行中的0替换为01,1替换为10. 给定行数 N 和序数 K,返回第 N 行中第 K个字符.(K从1开始) 例子: 输入: N = 1, K = 1 输出: 0 输入: N = 2, K = 1 输出: 0 输入: N = 2, K = 2 输出: 1 输入: N = 4, K = 5 输出: 1 解释: 第一行: 0 第二行: 01 第三行: 0110 第四行: 01101001 注意: N 的范围 [1, 30]. K…

class Solution { public: int kthGrammar(int N, int K) { return helper(N, K, false); } int helper(int n, int k, bool reverse) { ) return reverse; << (n-); ; if (k <= half) , k, reverse); else , k-half, !reverse); } }; /* lvl1: 0 lvl2: 0 1 lvl3: 0…

题目如下: 解题思路:直接把每行的数据计算出来肯定是不行的,因为N最大是30,那个第N行长度就是2^30次方,这显然不可取.那么就只能找规律了,我采取的是倒推法.例如假如我们要求出第四行第七个元素的值,记为[4,7],显然[4,7]是从第三行的第四个元素计算得来的[3,4],依次类推接下来是[2,2] ,[1,1] .这样就形成了一个[4,7] -> [3,4] ->[2,2] -> [1,1]递推链. 而[1,1]的值是确定的就是0,那么[2,2]就是0转换成01的第二个元素1,[3,…

Given a non-negative integer num represented as a string, remove k digits from the number so that the new number is the smallest possible. Note: The length of num is less than 10002 and will be ≥ k. The given num does not contain any leading zero. Ex…

You are given two integer arrays nums1 and nums2 sorted in ascending order and an integer k. Define a pair (u,v) which consists of one element from the first array and one element from the second array. Find the k pairs (u1,v1),(u2,v2) ...(uk,vk) wit…

Given a non-empty array of integers, return the k most frequent elements. For example,Given [1,1,1,2,2,3] and k = 2, return [1,2]. Note: You may assume k is always valid, 1 ≤ k ≤ number of unique elements.    Your algorithm's time complexity must be…