摘要：
Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree is symmetric: 1 / \ ... 阅读全文
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Given a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as a binary tree in which the depth... 阅读全文
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You are climbing a stair case. It takesnsteps to reach to the top.Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb... 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.水题不解释，一A，... 阅读全文
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Given an array and a value, remove all instances of that value in place and return the new length.The order of elements can be changed. It doesn't mat... 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
摘要：
You are climbing a stair case. It takesnsteps to reach to the top.Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb... 阅读全文