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  1. import java.util.*;
  2. import java.lang.*;
  3. import java.io.*;
  4.  
  5. class MidApp
  6. {
  7.    //private static final int ARRAY_SIZE_MAX = 1024;
  8.  
  9.    public static Integer scanInteger( Scanner in )
  10.    {
  11. 	   return ( ( in.hasNextInt() ) ? in.nextInt() : null );
  12.    }
  13.  
  14.    public static Double scanDouble( Scanner in )
  15.    {
  16. 	   return ( ( in.hasNextDouble() ) ? in.nextDouble() : null );
  17.    }
  18.  
  19.    public static void main( String[] args )
  20.    {
  21.       // рабочие переменные
  22.       double avg = 0;
  23.       double disp = 0;
  24.       int k = 0;
  25.       int n = 0;
  26.  
  27.       Scanner in = new Scanner(System.in);      
  28.  
  29.       n = scanInteger( in );
  30.  
  31.       if( n <= 0 )
  32.       {
  33.       	 System.out.printf("error: wrong value of n\n");
  34.          return;
  35.       }
  36.  
  37.       double[] x = new double[ n ];
  38.  
  39.       k = n; 
  40.  
  41.       // вычисление среднего значения
  42.       for( int i = 0; i < k; i++ )
  43.       {
  44.          x[i] = scanDouble( in );
  45.          if( x[i] < 1 )
  46.          {
  47.             System.out.printf("error: incomplete input of x\n");
  48.             return;
  49.          }
  50.          avg += x[i];
  51.       }
  52.       avg /= k;
  53.  
  54.       in.close();
  55.  
  56.       // вычисление дисперсии
  57.       for( int i = 0; i < k; i++ )
  58.       {
  59.         disp += ( x[i] - avg ) * ( x[i] - avg );
  60.       }
  61.       disp /= ( k - 1 );
  62.  
  63.       // вывод результата
  64.       System.out.printf("%f\n", avg);
  65.       System.out.printf("%f", disp);
  66.    }
  67. }
  68.  
Success #stdin #stdout 0.17s 321280KB
comments (?)
stdin 
3 4 5 8
stdout 
5.666667
4.333333
https://ideone.com/648LHr
language:
Java (12.0.1)
created:
9 years ago
visibility:
public

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