题目如下: 解题思路:本题求的是第N个Magical Number,我们可以很轻松的知道这个数的取值范围 [min(A,B), N*max(A,B)].对于知道上下界求具体数字的题目,可以考虑用二分查找.这样题目就从找出第N个Magical Number变成判断一个数是否是第N个Magical Number.假设n是其中一个Magical Number,显然n满足 n % A == 0 或者 n % B == 0.对于A来说,从A到n之间有n/A个Magical Number,而对B来说是n/B…

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://leetcode.com/problems/n-th-tribonacci-number/ 题目描述 The Tribonacci sequence Tn is defined as follows: T0 = 0, T1 = 1, T2 = 1, and Tn+3 = Tn + Tn+1 + Tn+2 fo…

题目如下: The Tribonacci sequence Tn is defined as follows: T0 = 0, T1 = 1, T2 = 1, and Tn+3 = Tn + Tn+1 + Tn+2for n >= 0. Given n, return the value of Tn. Example 1: Input: n = 4 Output: 4 Explanation: T_3 = 0 + 1 + 1 = 2 T_4 = 1 + 1 + 2 = 4 Example 2:…

A positive integer is magical if it is divisible by either A or B. Return the N-th magical number.  Since the answer may be very large, return it modulo 10^9 + 7. Example 1: Input: N = 1, A = 2, B = 3 Output: 2 Example 2: Input: N = 4, A = 2, B = 3 O…

A positive integer is magical if it is divisible by either A or B. Return the N-th magical number.  Since the answer may be very large, return it modulo 10^9 + 7. Example 1: Input: N = 1, A = 2, B = 3 Output: 2 Example 2: Input: N = 4, A = 2, B = 3 O…

题目等级:Easy 题目描述: Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward. Example 1: Input: 121 Output: true Example 2: Input: -121 Output: false Explanation: From left to right, it reads -12…

题目如下: 解题思路:几乎和[leetcode]719. Find K-th Smallest Pair Distance 的方法一样.只不过一个是减法一个是乘法,还有一点区别是[leetcode]719. Find K-th Smallest Pair Distance中i-j和j-i只算一个元素,而本题中i*j与j*i算两个元素. 代码如下: class Solution(object): def findKthNumber(self, m, n, k): """ :ty…

problem 1137. N-th Tribonacci Number solution: class Solution { public: int tribonacci(int n) { ) ; || n==) ; , t1 = , t2 = , t3 = ; ; i<=n; i++) { t3 = t0+t1+t2; t0 = t1; t1 = t2; t2 = t3; } return t3; } };     参考 1. Leetcode_easy_1137. N-th Tribona…

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/reach-a-number/description/ 题目描述 Find the nth digit of the infinite integer sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, - Note: n is posit…

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 数学 日期 题目地址:https://leetcode.com/problems/reach-a-number/description/ 题目描述 You are standing at position 0 on an infinite number line. There is a goal at position target. On each…

problem 414. Third Maximum Number solution 思路:用三个变量first, second, third来分别保存第一大.第二大和第三大的数,然后遍历数组. class Solution { public: int thirdMax(vector<int>& nums) { //1.LONG_MIN; long first = LONG_MIN, second = LONG_MIN, third = LONG_MIN;// for(auto a: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 Java解法 Python解法 日期 题目地址:https://leetcode.com/problems/convert-a-number-to-hexadecimal/ 题目描述 Given an integer, write an algorithm to convert it to hexadecimal. For negative inte…

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 替换最大值数组 使用set 三个变量 日期 题目地址:https://leetcode.com/problems/third-maximum-number/description/ 题目描述 Given a non-empty array of integers, return the third maximum number in this arr…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/valid-triangle-number/description/ 题目描述: Given an array consists of non-negative integers, your task is to count the number of triplets chosen from the array t…

题目简述: Given a linked list, remove the nth node from the end of list and return its head. For example, Given linked list: 1->2->3->4->5, and n = 2. After removing the second node from the end, the linked list becomes 1->2->3->5. Note:…

Given a linked list, remove the nth node from the end of list and return its head. For example, Given linked list: 1->2->3->4->5, and n = 2. After removing the second node from the end, the linked list becomes 1->2->3->5. 思路: 最基本的思路肯定…

Excel Sheet Column Number Related to question Excel Sheet Column Title Given a column title as appear in an Excel sheet, return its corresponding column number. For example: A -> 1 B -> 2 C -> 3 ... Z -> 26 AA -> 27 AB -> 28   class Solu…

这道题是LeetCode里的第171道题. 题目描述: 给定一个Excel表格中的列名称,返回其相应的列序号. 例如, A -> 1 B -> 2 C -> 3 ... Z -> 26 AA -> 27 AB -> 28 ... 示例 1: 输入: "A" 输出: 1 示例 2: 输入: "AB" 输出: 28 示例 3: 输入: "ZY" 输出: 701 26进制算法题-- 解题代码: class Solut…

这道题是LeetCode里的第19道题. 题目要求: 给定一个链表,删除链表的倒数第 n 个节点,并且返回链表的头结点. 示例: 给定一个链表: 1->2->3->4->5, 和 n = 2. 当删除了倒数第二个节点后,链表变为 1->2->3->5. 说明: 给定的 n 保证是有效的. 进阶: 你能尝试使用一趟扫描实现吗? 先求链表长度的暴力法我就不讲了. 关于一趟实现的办法就是先让 back 先走 n 次,此时 front 和 back 产生了长度为 n 的间…

题目如下: Given head which is a reference node to a singly-linked list. The value of each node in the linked list is either 0 or 1. The linked list holds the binary representation of a number. Return the decimal value of the number in the linked list. Ex…

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 桶排序 日期 题目地址:https://leetcode-cn.com/problems/check-if-a-number-is-majority-element-in-a-sorted-array/ 题目描述 Given an array of integers A`, return the largest integer that only oc…

题目如下: 解题思路:总结一下这么几点,一出一进,优先级队列排序,保证每次输出的都是当前的最小值.解法大致如图: 代码如下: #include<map> #include<queue> using namespace std; struct node { node(int k,int v) { key = k; val = v; } friend bool operator< (node n1, node n2) { return n1.val > n2.val; }…

[LeetCode]481. Magical String 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/magical-string/description/ 题目描述: A magical string S consists of only '1' and '2' and obeys the f…

[LeetCode]Largest Number 解题报告 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/largest-number/#/description 题目描述: Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], t…

[LeetCode]375. Guess Number Higher or Lower II 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/guess-number-higher-or-lower-ii/description/ 题目描述: We are playing the Guess Game. The game is as f…

[LeetCode]792. Number of Matching Subsequences 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/number-of-matching-subsequences/description/ 题目描述: Given string S and a dictionary of words words,…

[LeetCode]137. Single Number II 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/single-number-ii/description/ 题目描述: Given an array of integers, every element appears three times except for one, which appears exactly once. Find that singl…

[LeetCode]306. Additive Number 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/additive-number/description/ 题目描述: Additive number is a string whose digits can form additive se…

[LeetCode]452. Minimum Number of Arrows to Burst Balloons 解题报告(Python) 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/minimum-number-of-arrows-to-burst-balloons/description/ 题目描述: There are a number of spherical balloons spread in two-dimensio…

[LeetCode]673. Number of Longest Increasing Subsequence 解题报告(Python) 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/number-of-longest-increasing-subsequence/description/ 题目描述: Given an unsorted array of integers, find the number of longest inc…