zoukankan      html  css  js  c++  java
  • 【leetcode】1636. Sort Array by Increasing Frequency

    题目如下:

    Given an array of integers nums, sort the array in increasing order based on the frequency of the values. If multiple values have the same frequency, sort them in decreasing order.

    Return the sorted array.

    Example 1:

    Input: nums = [1,1,2,2,2,3]
    Output: [3,1,1,2,2,2]
    Explanation: '3' has a frequency of 1, '1' has a frequency of 2, and '2' has a frequency of 3.
    

    Example 2:

    Input: nums = [2,3,1,3,2]
    Output: [1,3,3,2,2]
    Explanation: '2' and '3' both have a frequency of 2, so they are sorted in decreasing order.
    

    Example 3:

    Input: nums = [-1,1,-6,4,5,-6,1,4,1]
    Output: [5,-1,4,4,-6,-6,1,1,1]

    Constraints:

    • 1 <= nums.length <= 100
    • -100 <= nums[i] <= 100

    解题思路:先统计每个值出现的次数,然后排序即可。

    代码如下:

    class Solution(object):
        def frequencySort(self, nums):
            """
            :type nums: List[int]
            :rtype: List[int]
            """
            dic = {}
            for i in nums:
                dic[i] = dic.setdefault(i,0)+1
            pair = []
            for key,val in dic.iteritems():
                pair.append((key,val))
    
            def cmpf(p1,p2):
                if p1[1] != p2[1]:
                    return p1[1] - p2[1]
                return p2[0] - p1[0]
    
            pair.sort(cmp=cmpf)
    
            res = []
    
            for (key,val) in pair:
                res += [key] * val
    
            return res
  • 相关阅读:
    Jenkins
    ssh 免登录
    linux 远程执行命令
    Java WEB 笔记
    如何用新安装的jdk替换掉Linux系统默认jdk
    修改 File --> New 菜单内容
    java.security.NoSuchAlgorithmException: AES KeyGenerator not available
    JDK历史版本下载地址
    maven 核心概念
    spring boot: ConfigurationProperties
  • 原文地址:https://www.cnblogs.com/seyjs/p/14931266.html
Copyright © 2011-2022 走看看