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Find the total area covered by tworectilinearrectangles in a2Dplane.Each rectangle is defined by its bottom left corner and top right corner as shown ... 阅读全文
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Implement the following operations of a stack using queues.push(x) -- Push element x onto stack.pop() -- Removes the element on top of the stack.top()... 阅读全文
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Invert a binary tree. 4 / \ 2 7 / \ / \1 3 6 9to 4 / \ 7 2 / \ / \9 6 3 1思路：利用temp进行交换，采用递归从顶至下，终止条件本身为空或者是叶子节点。... 阅读全文
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Given a sorted integer array without duplicates, return the summary of its ranges.For example, given[0,1,2,4,5,7], return["0->2","4->5","7"].思路:采用双指针 ... 阅读全文
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Given an integer, write a function to determine if it is a power of two.判断一个数是不是2的幂。思路，找出该数中二进制位1的个数时间复杂度：O(n)代码： public boolean isPowerOfTwo(int n... 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 o... 阅读全文
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Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.According to thedefinition of LCA on Wikipedia: ... 阅读全文
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二叉树 在计算机科学中，二叉树是每个节点最多有两个子树的树结构。通常子树被称作“左子树”（left subtree）和“右子树”（right subtree）。二叉树常被用于实现二叉查找树和二叉堆。 二叉树的每个结点至多只有二棵子树(不存在度大于2的结点)，二叉树的子树有左右之分，次序不能颠倒。二叉 阅读全文