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Given an array of integers nums, you start with an initial positive value startValue. In each iteration, you calculate the step by step sum of startVa 阅读全文
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Given an array of integers arr, a lucky integer is an integer which has a frequency in the array equal to its value. Return a lucky integer in the arr 阅读全文
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Given an integer n. Each number from 1 to n is grouped according to the sum of its digits. Return how many groups have the largest size. 对1-n的数分组，分组规则 阅读全文
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Given an array of distinct integers arr, find all pairs of elements with the minimum absolute difference of any two elements. Return a list of pairs i 阅读全文
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On an 8 x 8 chessboard, there is one white rook. There also may be empty squares, white bishops, and black pawns. These are given as characters 'R', ' 阅读全文
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The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding one 阅读全文
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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 can only be 阅读全文
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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 such that the 阅读全文
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Given an array A of strings made only from lowercase letters, return a list of all characters that show up in all strings within the list (including d 阅读全文
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Given two integer arrays arr1 and arr2, and the integer d, return the distance value between the two arrays. The distance value is defined as the numb 阅读全文
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Given a m * n matrix mat of ones (representing soldiers) and zeros (representing civilians), return the indexes of the k weakest rows in the matrix or 阅读全文
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Given an array A of non-negative integers, half of the integers in A are odd, and half of the integers are even. Sort the array so that whenever A[i] 阅读全文
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Students are asked to stand in non-decreasing order of heights for an annual photo. Return the minimum number of students that must move in order for 阅读全文
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Given an array of 2n integers, your task is to group these integers into n pairs of integer, say (a1, b1), (a2, b2), ..., (an, bn) which makes sum of 阅读全文
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Given a m * n matrix of distinct numbers, return all lucky numbers in the matrix in any order. A lucky number is an element of the matrix such that it 阅读全文
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Given an array of integers A sorted in non-decreasing order, return an array of the squares of each number, also in sorted non-decreasing order. nlog做 阅读全文
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Given an array of unique integers salary where salary[i] is the salary of the employee i. Return the average salary of employees excluding the minimum 阅读全文
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Given an array A of non-negative integers, return an array consisting of all the even elements of A, followed by all the odd elements of A. You may re 阅读全文
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Given two integer arrays of equal length target and arr. In one step, you can select any non-empty sub-array of arr and reverse it. You are allowed to 阅读全文
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Given a binary matrix A, we want to flip the image horizontally, then invert it, and return the resulting image. To flip an image horizontally means t 阅读全文