1. 题目要求 Given a non-empty list of words, return the k most frequent elements. Your answer should be sorted by frequency from highest to lowest. If two words have the same frequency, then the word with the lower alphabetical order comes first. 2. Code…

463. Island Perimeterhttps://leetcode.com/problems/island-perimeter/就是逐一遍历所有的cell,用分离的cell总的的边数减去重叠的边的数目即可.在查找重叠的边的数目的时候有一点小技巧,就是沿着其中两个方向就好,这种题目都有类似的规律,就是可以沿着上三角或者下三角形的方向来做.一刷一次ac,但是还没开始注意codestyle的问题,需要再刷一遍. class Solution { public: int islandPerime…


Given
 an 
arbitrary
 ransom
 note
 string 
and 
another 
string 
containing 
letters from
 all 
the 
magazines,
 write 
a 
function 
that 
will 
return 
true 
if 
the 
ransom 
 note 
can 
be 
constructed 
from 
the 
magazines ; 
otherwise, 
it 
wil…

Given a non-empty list of words, return the k most frequent elements. Your answer should be sorted by frequency from highest to lowest. If two words have the same frequency, then the word with the lower alphabetical order comes first. Example 1: Inpu…

https://leetcode.com/problems/top-k-frequent-words/ Given a non-empty list of words, return the k most frequent elements. Your answer should be sorted by frequency from highest to lowest. If two words have the same frequency, then the word with the l…

692. 前K个高频单词 给一非空的单词列表,返回前 k 个出现次数最多的单词. 返回的答案应该按单词出现频率由高到低排序.如果不同的单词有相同出现频率,按字母顺序排序. 示例 1: 输入: ["i", "love", "leetcode", "i", "love", "coding"], k = 2 输出: ["i", "love"] 解析: &…

public class Solution { public boolean canConstruct(String ransomNote, String magazine) { int[] ransomNum = new int[256]; int[] magNum = new int[256]; for (int i = 0; i < 256; i++) { ransomNum[i] = magNum[i] = 0; } for (int i = 0; i < ransomNote.len…

Discription Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice. Example: Given nums = [2…

这个题的排序是用的PriorityQueue实现自动排列,优先队列用的是堆排序,堆排序请看:http://www.cnblogs.com/stAr-1/p/7569706.html 自定义了优先队列的排序方法,lambda表达式该复习下了... public List<String> topKFrequent(String[] words, int k) { /* 1.建立字符串和出现频率的映射 2.用优先队列PriorityQueue实现排序(相同频率用compareTo方法) 4.挑选出前…

Given a non-empty array of integers, return the k most frequent elements. Example 1: Input: nums = [1,1,1,2,2,3], k = 2 Output: [1,2] Example 2: Input: nums = [1], k = 1 Output: [1] Note: You may assume k is always valid, 1 ≤ k ≤ number of unique ele…