leetcode

You are given row x col grid representing a map where grid[i][j] = 1 represents land and grid[i][j] = 0 represents water. Grid cells are co…

You are given an array of strings words and a string chars. A string is good if it can be formed by characters from chars (each character c…

You are given row x col grid representing a map where grid[i][j] = 1 represents land and grid[i][j] = 0 represents water. Grid cells are co…

You are given an array of strings words and a string chars. A string is good if it can be formed by characters from chars (each character c…

Given an array of integers arr, write a function that returns true if and only if the number of occurrences of each value in the array is u…

In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated N times. Return the element repeated …

Given an array of integers nums. A pair (i,j) is called good if nums[i] == nums[j] and i < j. Return the number of good pairs. 根据题意，只需…

Given the array nums, for each nums[i] find out how many numbers in the array are smaller than it. That is, for each nums[i] you have to co…

You're given strings jewels representing the types of stones that are jewels, and stones representing the stones you have. Each character i…

Given the array nums, for each nums[i] find out how many numbers in the array are smaller than it. That is, for each nums[i] you have to co…

Given an array of integers nums. A pair (i,j) is called good if nums[i] == nums[j] and i < j. Return the number of good pairs. 根据题意，只需…

Given an array target and an integer n. In each iteration, you will read a number from list = {1,2,3..., n}. Push: Read a new element from …

Given a string S of lowercase letters, a duplicate removal consists of choosing two adjacent and equal letters, and removing them. We repea…

Given a m * n matrix mat of integers, sort it diagonally in ascending order from the top-left to the bottom-right then return the sorted ar…

Given an array of numbers arr. A sequence of numbers is called an arithmetic progression if the difference between any two consecutive elem…

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 strings s and t , write a function to determine if t is an anagram of s. 根据题意，因为包含的都是小写字母，所以遍历 26 个英文字母，只要长度相同，且 s 和 t 中包含的每个字母数量…

Given an array of integers nums, sort the array in increasing order based on the frequency of the values. If multiple values have the same …

Given two arrays arr1 and arr2, the elements of arr2 are distinct, and all elements in arr2 are also in arr1. Sort the elements of arr1 suc…

Given an integer array arr. You have to sort the integers in the array in ascending order by the number of 1's in their binary representati…