12 2020 档案
摘要：Implement pow(x, n), which calculates x raised to the power n (i.e. xn). 方法一： 递归 public double quickMul(double x, long N) { if (N == 0) { return 1.0;
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摘要：Given an array of strings strs, group the anagrams together. You can return the answer in any order. An Anagram is a word or phrase formed by rearrang
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摘要：You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise). You have to rotate the image in-place, which means
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摘要：Given a collection of numbers, nums, that might contain duplicates, return all possible unique permutations in any order. 方法： 回溯法，去重 boolean[] vis; pu
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摘要：Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any order. 方法 ： 回溯法。 public List<List<Int
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摘要：Given an array of non-negative integers nums, you are initially positioned at the first index of the array. Each element in the array represents your
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摘要：Given an input string (s) and a pattern (p), implement wildcard pattern matching with support for '?' and '*' where: '?' Matches any single character.
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摘要：Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2, also represented as a string. Note: You mus
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摘要：Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining. Input:
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摘要：Given an unsorted integer array nums, find the smallest missing positive integer. Follow up: Could you implement an algorithm that runs in O(n) time a
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摘要：Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numb
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摘要：Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen nu
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摘要：The count-and-say sequence is a sequence of digit strings defined by the recursive formula: countAndSay(1) = "1" countAndSay(n) is the way you would "
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摘要：Write a program to solve a Sudoku puzzle by filling the empty cells. A sudoku solution must satisfy all of the following rules: Each of the digits 1-9
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摘要：Determine if a 9 x 9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules: Each row must contain the dig
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摘要：Given a sorted array of distinct integers and a target value, return the index if the target is found. If not, return the index where it would be if i
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摘要：Given an array of integers nums sorted in ascending order, find the starting and ending position of a given target value. If target is not found in th
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摘要：You are given an integer array nums sorted in ascending order, and an integer target. Suppose that nums is rotated at some pivot unknown to you before
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摘要：Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring. Input: s = "(()"O
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摘要：Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers. If such an arrangement is not pos
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摘要：You are given a string s and an array of strings words of the same length. Return all starting indices of substring(s) in s that is a concatenation of
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摘要：Given two integers dividend and divisor, divide two integers without using multiplication, division, and mod operator. Return the quotient after divid
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摘要：Implement strStr(). Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Clarification: What shoul
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摘要：Given an array nums and a value val, remove all instances of that value in-place and return the new length. Do not allocate extra space for another ar
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摘要：Given a sorted array nums, remove the duplicates in-place such that each element appears only once and returns the new length. Do not allocate extra s
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摘要：Given a linked list, reverse the nodes of a linked list k at a time and return its modified list. k is a positive integer and is less than or equal to
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摘要：Given a linked list, swap every two adjacent nodes and return its head. You may not modify the values in the list's nodes. Only nodes itself may be ch
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摘要：You are given an array of k linked-lists lists, each linked-list is sorted in ascending order. Merge all the linked-lists into one sorted linked-list
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摘要：Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses. Input: n = 3Output: ["((()))","(()())","(())()
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摘要：Merge two sorted linked lists and return it as a new sorted list. The new list should be made by splicing together the nodes of the first two lists. I
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摘要：Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. An input string is valid if:
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摘要：算法定义： 编写一段计算机程序一般都是实现一种已有的方法来解决某个问题。 这种方法大多和使用的编程语言无关--它适用于各种计算机以及编程语言。是这种方法而非计算机程序本身描述来解决问题的步骤。在计算机科学领域，我们用算法这个词来描述一种有限、确定、有效的并适合用计算机程序来实现的解决问题的方法。 我
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摘要：Given the head of a linked list, remove the nth node from the end of the list and return its head. Follow up: Could you do this in one pass? Input: he
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摘要：Given an array nums of n integers and an integer target, are there elements a, b, c, and d in nums such that a + b + c+ d = target? Find all unique qu
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摘要：Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. Return the answer in any
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摘要：Given an array nums of n integers and an integer target, find three integers in nums such that the sum is closest to target. Return the sum of the thr
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摘要：Given an array nums of n integers, are there elements a, b, c in nums such that a + b + c = 0? Find all unique triplets in the array which gives the s
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