在Delphi控制台应用程序

Question

我重拍我的代码和它的外观一样，平均数：

{$APPTYPE CONSOLE} 

type vector = array[1..100] of integer; 
var a:vector; 
var i,n:integer; 
var br:integer; 
var sum,average:real; 

begin 
    write('Enter number elements of the array: '); readln(n); 
    for i:=1 to n do 
     begin 
     write('Enter ' ,i, ' element: '); readln(a[i]); 
     end; 
     br:=0; 
     sum:=0; 
      for i:=1 to n do 
      if not(odd(a[i])) and (odd(i)) then 
      sum:=sum+a[i]; 
      br:=br+1; 
      average:=sum/br; 
      writeln('average= ',average:5:3); 
      readln; 
end. 

但是，当我开始我的计划其只发现的总和，并且计数器（BR）心不是工作，只计算总和。你现在可以帮助我，取决于我的代码:)！

Answer 1

有必要把begin和end，所以br正确递增：

if not(odd(a[i])) and (odd(i)) then 
Begin 
     sum:=sum+a[i]; 
     br:=br+1; 
End; 
average:=sum/br; 

Answer 2

试试这个：

program Project1; 

{$APPTYPE CONSOLE} 
{$R *.res} 

uses 
    System.SysUtils; 

type 
    TVector = array of integer; 

var 
    a: TVector; 
    i, n: integer; 
    ElSum, Elements: integer; 

begin 
    write('Enter number of elements: '); 
    readln(n); 
    SetLength(a, n); 
    for i := 1 to n do 
    begin 
    write('Enter ', i, ' element: '); 
    readln(a[i - 1]); 
    end; 
    ElSum := 0; 
    Elements := 0; 
    for i := 1 to n do 
    if not(odd(a[i - 1])) and (odd(i)) then 
    begin 
     inc(ElSum, a[i - 1]); 
     inc(Elements); 
    end; 
    if Elements <> 0 then 
    writeln('The average is: ' + floattostr(ElSum/Elements)) 
    else 
    writeln('Can not divide by 0'); 
    readln; 
end. 

附加

在这种情况下，数据将在输入时进行分析。我假设你将来不需要数组的元素。这就是为什么我不存储数组中的值。我也跳过FloatToStr函数。

program Project1; 

{$APPTYPE CONSOLE} 
{$R *.res} 
//We skip uses System.SysUtils; 
var 
    i, n, CurrentInteger, 
    ElSum, Elements: integer; 

begin 
    ElSum := 0; 
    Elements := 0; 
    write('Enter number of elements: '); 
    readln(n); 
    for i := 1 to n do 
    begin 
    write('Enter ', i, ' element: '); 
    readln(CurrentInteger); 
    if not(odd(CurrentInteger)) and (odd(i)) then 
    begin 
     inc(ElSum, CurrentInteger); 
     inc(Elements); 
    end; 
    end; 

    if Elements <> 0 then 
    begin 
     write('The average is: '); 
     writeln(ElSum/Elements:5:3)//we write it instead of FloatToStr 
    end 
    else 
    writeln('Can not divide by 0'); 
    readln; 

end. 

Answer 3

使用内置的例行[System.]Math.Mean：

program Project1; 

{$APPTYPE CONSOLE} 

uses 
    System.SysUtils, System.Types, System.Math; 

var 
    Count: Integer; 
    I: Integer; 
    Values: TSingleDynArray; 

begin 
    try 
    Write('Enter number of elements of the array: '); 
    ReadLn(Count); 
    SetLength(Values, Count); 
    for I := 0 to Count - 1 do 
    begin 
     Write('Enter element ', I + 1, ': '); 
     ReadLn(Values[I]); 
    end; 
    WriteLn('Average = ', Mean(Values):5:3); 
    except 
    on E: Exception do 
     Writeln(E.ClassName, ': ', E.Message); 
    end; 
    Readln; 
end.