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Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.N... 阅读全文
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Given a linked list, swap every two adjacent nodes and return its head.For example, Given 1->2->3->4, you should return the list as 2->1->4->3.Your al... 阅读全文
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Given a collection of numbers, return all possible permutations.For example, [1,2,3] have the following permutations: [1,2,3], [1,3,2], [2,1,3], [2,3,... 阅读全文
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Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, ... 阅读全文
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Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists./** * Def... 阅读全文
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Implement the following operations of a queue using stacks.push(x) – Push element x to the back of queue. pop() – Removes the element from in front of... 阅读全文
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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 transaction ... 阅读全文
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Write an algorithm to determine if a number is “happy”.A happy number is a number defined by the following process: Starting with any positive integer... 阅读全文
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The gray code is a binary numeral system where two successive values differ in only one bit.Given a non-negative integer n representing the total numb... 阅读全文
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Write a program to check whether a given number is an ugly number.Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For exam... 阅读全文
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Given a sorted linked list, delete all duplicates such that each element appear only once.For example, Given 1->1->2, return 1->2. Given 1->1->2->3->3... 阅读全文
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Suppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).Find the minimum element.Yo... 阅读全文
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Find the contiguous subarray within an array (containing at least one number) which has the largest sum.For example, given the array [−2,1,−3,4,−1,2,1... 阅读全文
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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 can you cli... 阅读全文