leetcode

Given two strings s and t , write a function to determine if t is an anagram of s. 根据题意，就是找出 s 和 t 两个字符串是不是同字母异序词，时间复杂度为 O(N)，空间复杂度为 O(1)。 …

Given an array A of positive lengths, return the largest perimeter of a triangle with non-zero area, formed from 3 of these lengths. If it …

Given two arrays, write a function to compute their intersection. 根据题意，就是找出交集列表，时间复杂度 O(N+M)，O(N) 用于 nums1 转换成 set , O(M) 用于 nums2 转换成 set …

You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint …

iven an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum. 根据题…

Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one …

On a staircase, the i-th step has some non-negative cost cost[i] assigned (0 indexed). Once you pay the cost, you can either climb one or t…

You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb 1 or 2 steps. In how many distinct ways…

Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array. 根据题意肯定用公式计算方法最快，就是把 M…

Given a 2D integer matrix M representing the gray scale of an image, you need to design a smoother to make the gray scale of each cell beco…

We have two special characters. The first character can be represented by one bit 0. The second character can be represented by two bits (1…

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times. You may assu…

Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number. T…

Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at least twice…

Given an array of integers where 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once. Find all the elements…

Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements. 就是把左右…

Given a binary array, find the maximum number of consecutive 1s in this array. 遍历所有的数组元素，遇到 1 就计数，遇到 0 就更新一次最大个数 result，直到最后遍历完所有元素。 每日格言：每…

Given an array A of integers, return true if and only if we can partition the array into three non-empty parts with equal sums. Formally, w…

An array is monotonic if it is either monotone increasing or monotone decreasing. An array A is monotone increasing if for all i <= j, A[i]…

We have an array A of integers, and an array queries of queries. For the i-th query val = queries[i][0], index = queries[i][1], we add val …