算法设计（未排序数组的均值和中位数的程序） _均值

本文概述

C ++
Java
Python3
C#
的PHP

给定?大小未排序的数组, 找到平均值和中位数。

数组的平均值=(所有元素的总和)/(元素数量)

中位数
当n为奇数时, 大小为n的排序数组的定义为中间元素, 而当n为偶数时, 定义为中间两个元素的平均值。
由于此处未对数组进行排序, 因此我们首先对数组进行排序, 然后应用上述公式。
例子：

Input: a[] = {1, 3, 4, 2, 6, 5, 8, 7} Output : Mean = 4.5 Median = 4.5 Sum of the elements is 1 + 3 + 4 + 2 + 6 + 5 + 8 + 7 = 36 Mean = 36/8 = 4.5 Since number of elements are even, median is average of 4th and 5th largest elements. which means (4 + 5)/2 = 4.5Input: a[] = {4, 4, 4, 4, 4} Output : Mean = 4 Median = 4

推荐：请尝试以下方法
{IDE}
首先, 在继续解决方案之前。
下面是代码实现：
C ++

// CPP program to find mean and median of // an array #include < bits/stdc++.h> using namespace std; // Function for calculating mean double findMean( int a[], int n) { int sum = 0; for ( int i = 0; i < n; i++) sum += a[i]; return ( double )sum / ( double )n; } // Function for calculating median double findMedian( int a[], int n) { // First we sort the array sort(a, a + n); // check for even case if (n % 2 != 0) return ( double )a[n / 2]; return ( double )(a[(n - 1) / 2] + a[n / 2]) / 2.0; } // Driver code int main() { int a[] = { 1, 3, 4, 2, 7, 5, 8, 6 }; int n = sizeof (a) / sizeof (a[0]); // Function call cout < < "Mean = " < < findMean(a, n) < < endl; cout < < "Median = " < < findMedian(a, n) < < endl; return 0; }

Java

// Java program to find mean // and median of an array import java.util.*; class GFG { // Function for calculating mean public static double findMean( int a[], int n) { int sum = 0 ; for ( int i = 0 ; i < n; i++) sum += a[i]; return ( double )sum / ( double )n; } // Function for calculating median public static double findMedian( int a[], int n) { // First we sort the array Arrays.sort(a); // check for even case if (n % 2 != 0 ) return ( double )a[n / 2 ]; return ( double )(a[(n - 1 ) / 2 ] + a[n / 2 ]) / 2.0 ; } // Driver code public static void main(String args[]) { int a[] = { 1 , 3 , 4 , 2 , 7 , 5 , 8 , 6 }; int n = a.length; // Function call System.out.println( "Mean = " + findMean(a, n)); System.out.println( "Median = " + findMedian(a, n)); } } // This article is contributed by Anshika Goyal.

Python3

# Python3 program to find mean # and median of an array # Function for calculating mean def findMean(a, n): sum = 0 for i in range ( 0 , n): sum + = a[i] return float ( sum / n) # Function for calculating median def findMedian(a, n): # First we sort the array sorted (a) # check for even case if n % 2 ! = 0 : return float (a[ int (n / 2 )]) return float ((a[ int ((n - 1 ) / 2 )] + a[ int (n / 2 )]) / 2.0 ) # Driver code a = [ 1 , 3 , 4 , 2 , 7 , 5 , 8 , 6 ] n = len (a) # Function call print ( "Mean =" , findMean(a, n)) print ( "Median =" , findMedian(a, n)) # This code is contributed by Smitha Dinesh Semwal

// C# program to find mean // and median of an array using System; class GFG { // Function for // calculating mean public static double findMean( int [] a, int n) { int sum = 0; for ( int i = 0; i < n; i++) sum += a[i]; return ( double )sum / ( double )n; } // Function for // calculating median public static double findMedian( int [] a, int n) { // First we sort // the array Array.Sort(a); // check for // even case if (n % 2 != 0) return ( double )a[n / 2]; return ( double )(a[(n - 1) / 2] + a[n / 2]) / 2.0; } // Driver Code public static void Main() { int [] a = { 1, 3, 4, 2, 7, 5, 8, 6 }; int n = a.Length; // Function call Console.Write( "Mean = " + findMean(a, n) + "\n" ); Console.Write( "Median = " + findMedian(a, n) + "\n" ); } } // This code is contributed by Smitha .

的PHP

< ?php // PHP program to find mean // and median of an array // Function for calculating mean function findMean(& $a , $n ) { $sum = 0; for ( $i = 0; $i < $n ; $i ++) $sum += $a [ $i ]; return (double) $sum / (double) $n ; } // Function for // calculating median function findMedian(& $a , $n ) { // First we sort the array sort( $a ); // check for even case if ( $n % 2 != 0) return (double) $a [ $n / 2]; return (double)( $a [( $n - 1) / 2] + $a [ $n / 2]) / 2.0; } // Driver Code $a = array (1, 3, 4, 2, 7, 5, 8, 6); $n = sizeof( $a ); // Function call echo "Mean = " . findMean( $a , $n ). "\n" ; echo "Median = " . findMedian( $a , $n ); // This code is contributed // by ChitraNayal ?>

输出如下