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Given an array of non negative integers, you are initially positioned at the first index of the array. Each element in the array represents your maxim 阅读全文
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Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. For example, Given the following matrix: You 阅读全文
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You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). Follow up: Could you do this in place? 方阵顺时针旋转90度， 阅读全文
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Given an array of integers sorted in ascending order, find the starting and ending position of a given target value. Your algorithm's runtime complexi 阅读全文
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Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array whic 阅读全文
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Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. 阅读全文
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Given an unsorted integer array, find the first missing positive integer. For example , Your algorithm should run in $O(n)$ time and uses constant spa 阅读全文
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Given an array of integers, (n = size of array), some elements appear twice and others appear once . Find all the elements that appear twice in this a 阅读全文
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Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand. (i.e., might become ). You are given a target value to 阅读全文
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Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties: Integers in each row are sorted f 阅读全文