LeetCode: 451-Sort Characters By Frequency 解題紀錄
題目
Given a string s
, sort it in decreasing order based on the frequency of the characters. The frequency of a character is the number of times it appears in the string.
Given a string s
, sort it in decreasing order based on the frequency of the characters. The frequency of a character is the number of times it appears in the string.
今天在刷題的時候,看到一位分享自己解題思路的網友,他的程式碼中所有宣告的 vector
陣列,全部都使用 emplace_back()
。那時候我可看不明白了,從我在大學上課開始寫時,老師都是教寫 push_back()
的啊?
You are given an integer array matches
where matches[i] = [winneri, loseri]
indicates that the player winneri
defeated player loseri
in a match.
Given an integer array nums
, return the number of all the arithmetic subsequences of nums
.
ou are given two strings s
and t
consisting of only lowercase English letters.
Return the minimum number of characters that need to be appended to the end of s
so that t
becomes a subsequence of s
.
Given a positive integer n
, find the pivot integer x
such that:
1
and x
inclusively equals the sum of all elements between x
and n
inclusively.Given an m x n
grid of characters board
and a string word
, return true
if word
exists in the grid.
You are given an m x n
matrix maze
(0-indexed) with empty cells (represented as '.'
) and walls (represented as '+'
). You are also given the entrance
of the maze, where entrance = [entrancerow, entrancecol]
denotes the row and column of the cell you are initially standing at.