551. Student Attendance Record I-学生出勤记录 I
You are given a string representing an attendance recor... » 阅读全文
543. Diameter of Binary Tree-二叉树的直径
Given a binary tree, you need to compute the length of ... » 阅读全文
541. Reverse String II-反转字符串 II
Given a string and an integer k, you need to reverse th... » 阅读全文
530. Minimum Absolute Difference in BST-二叉搜索树的最小绝对差
Given a binary search tree with non-negative values, fi... » 阅读全文
521. Longest Uncommon Subsequence I-最长特殊序列 Ⅰ
给你两个字符串a和b，请返回这两个字符串中最长的特殊序列的长度。如果不存在，则返回-1。 「最长特殊序列」定义... » 阅读全文
520. Detect Capital-检测大写字母
Given a word, you need to judge whether the usage of ca... » 阅读全文
509. Fibonacci Number-斐波那契数
The Fibonacci numbers, commonly denoted F(n) form a seq... » 阅读全文
507. Perfect Number-完美数
A perfect number is a positive integer that is equal to... » 阅读全文
506. Relative Ranks-相对名次
Given scores of N athletes, find their relative ranks a... » 阅读全文
504. Base 7-七进制数
Given an integer, return its base 7 string representati... » 阅读全文