算法设计（整数流中的模式(运行整数)）

本文概述

C ++
Java
Python3
C#

假定正在从数据流读取整数。找出模式从第一个整数到最后一个整数, 到目前为止读取的所有元素的总数。

模式定义为出现最长时间的元素。如果两个或多个元素具有相同的最大频率, 则采用最后出现的那个。

例子：

【算法设计（整数流中的模式(运行整数)）】输入：stream [] = {2, 7, 3, 2, 5}
输出：2 7 3 2 2
说明：
运行Stream的模式计算如下：
Mode({2})= 2
Mode({2, 7} )= 7
Mode({2, 7, 3})= 3
Mode({2, 7, 3, 2})= 2
Mode({2, 7, 3, 2, 2})= 2
输入：stream [] = {3, 5, 9, 9, 2, 3, 3, 4}
输出：3 5 9 9 9 3 3 3

方法：想法是使用哈希图将元素映射到其频率。在逐一读取元素时, 将更新映射中元素的频率, 并且还将更新模式, 该模式将成为运行整数流的模式。
下面是上述方法的实现：
C ++

//C++ program to implement //the above approach #include< bits/stdc++.h> using namespace std; //Function that prints //the Mode values void findMode( int a[], int n) {//Map used to mp integers //to its frequency map< int , int> mp; //To store the maximum frequency int max = 0; //To store the element with //the maximum frequency int mode = 0; //Loop used to read the //elements one by one for ( int i = 0; i < n; i++) {//Updates the frequency of //that element mp[a[i]]++; //Checks for maximum Number //of occurrence if (mp[a[i]]> = max) {//Updates the maximum frequency max = mp[a[i]]; //Updates the Mode mode = a[i]; } cout < < mode < < " " ; } }//Driver Code int main() { int arr[] = { 2, 7, 3, 2, 5 }; int n = sizeof (arr)/sizeof (arr[0]); //Function call findMode(arr, n); return 0; } //This code is contributed by rutvik_56

Java

//Java implementation of the //above approachimport java.util.*; public class GFG {//Function that prints //the Mode values public static void findMode( int [] a, int n) { //Map used to map integers //to its frequency Map< Integer, Integer> map = new HashMap< > (); //To store the maximum frequency int max = 0 ; //To store the element with //the maximum frequency int mode = 0 ; //Loop used to read the //elements one by one for ( int i = 0 ; i < n; i++) {//Updates the frequency of //that element map.put(a[i], map.getOrDefault(a[i], 0 ) + 1 ); //Checks for maximum Number //of occurrence if (map.get(a[i])> = max) {//Updates the maximum frequency max = map.get(a[i]); //Updates the Mode mode = a[i]; }System.out.print(mode); System.out.print( " " ); } }//Driver Code public static void main(String[] args) { int arr[] = { 2 , 7 , 3 , 2 , 5 }; int n = arr.length; //Function Call findMode(arr, n); } }

Python3

# Python3 implementation of the # above approach# Function that prints # the Mode values def findMode(a, n):# Map used to mp integers # to its frequency mp = {}# To store the maximum frequency max = 0# To store the element with # the maximum frequency mode = 0# Loop used to read the # elements one by one for i in range (n): if a[i] in mp: mp[a[i]] + = 1 else : mp[a[i]] = 1# Checks for maximum Number # of occurrence if (mp[a[i]]> = max ):# Updates the maximum # frequency max = mp[a[i]]# Updates the Mode mode = a[i]print (mode, end = " " )# Driver Code arr = [ 2 , 7 , 3 , 2 , 5 ] n = len (arr)# Function call findMode(arr, n)# This code is contributed by divyeshrabadiya07

//C# implementation of the //above approach using System; using System.Collections.Generic; class GFG{//Function that prints //the Mode values public static void findMode( int [] a, int n) { //Map used to map integers //to its frequency Dictionary< int , int> map = new Dictionary< int , int> (); //To store the maximum frequency int max = 0; //To store the element with //the maximum frequency int mode = 0; //Loop used to read the //elements one by one for ( int i = 0; i < n; i++) {//Updates the frequency of //that element if (map.ContainsKey(a[i])) { map[a[i]] = map[a[i]] + 1; } else { map.Add(a[i], 1); }//Checks for maximum Number //of occurrence if (map[a[i]]> = max) {//Updates the maximum frequency max = map[a[i]]; //Updates the Mode mode = a[i]; } Console.Write(mode); Console.Write( " " ); } }//Driver Code public static void Main(String[] args) { int [] arr = {2, 7, 3, 2, 5}; int n = arr.Length; //Function Call findMode(arr, n); } }//This code is contributed by Amit Katiyar

输出如下：