摘要:
You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single ... 阅读全文
摘要:
Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters fo... 阅读全文
摘要:
Determine whether an integer is a palindrome. Do this without extra space.因为都额外空间有限制所以不能把他先转成字符串然后用两个指针扫了。负数不算回文数是因为前面多了个负号么=_= 这样的话我只能想到一个办法,就是反转一个数字... 阅读全文
摘要:
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
摘要:
Given a binary tree, determine if it is a valid binary search tree (BST).Assume a BST is defined as follows:The left subtree of a node contains only n... 阅读全文
摘要:
Given a string containing just the characters'(',')','{','}','['and']', determine if the input string is valid.The brackets must close in the correct ... 阅读全文
摘要:
Given a non-negative number represented as an array of digits, plus one to the number.The digits are stored such that the most significant digit is at... 阅读全文
摘要:
Given two binary trees, write a function to check if they are equal or not.Two binary trees are considered equal if they are structurally identical an... 阅读全文
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
摘要:
Given a binary tree, find its minimum depth.The minimum depth is the number of nodes along the shortest path from the root node down to the nearest le... 阅读全文