unit1.pas

完成多项式的运算

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    Label1: TLabel;
    Edit1: TEdit;
    Button1: TButton;
    Button2: TButton;
    ListBox1: TListBox;
    memo1: TMemo;
    Button3: TButton;
    Label2: TLabel;
    Edit2: TEdit;
    Label3: TLabel;
    Timer1: TTimer;
    procedure Edit1KeyPress(Sender: TObject; var Key: Char);
    procedure Timer1Timer(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }

  end;
 const max=100;
var
  Form1: TForm1;
    flag:boolean;
    number:array[0..max] of integer;
   symbol:array[1..max] of char;
   s,t,tr:string;
    i,p,j,code,kk,count,mm,tt:integer;

implementation

{$R *.dfm}
    procedure push;
 begin
  inc(count);
  inc(p);symbol[p]:=s[i];

 end;
procedure pop;
 begin
  inc(count);
  dec(p);
 case symbol[p+1] of
 '+':inc(number[p],number[p+1]);
 '-':dec(number[p],number[p+1]);
 '*':number[p]:=number[p]*number[p+1];
 '/':
 begin
   if number[p+1]=0 then
    begin
     showmessage('您的表达式存在除数为0的情况，请确认后重输！');
     flag:=false;
     exit;
    end;
   number[p]:=number[p] div number[p+1];
 end;
 '%':
  begin
   if number[p+1]=0 then
    begin
     showmessage('您的表达式存在模数为0的情况，请确认后重输！');
     flag:=false;
     exit;
    end;
   number[p]:=number[p] mod number[p+1];
  end;
 '^': begin
       tt:=number[p];
       if number[p+1]=0 then
        begin
         number[p]:=1;
         exit
        end;
       if number[p+1]<0 then
        begin
         showmessage('本人能力，无法显示小数，指数请为正整数，谢谢！');
         flag:=false;
         exit;
        end;
       for kk:=1 to number[p+1]-1 do
       number[p]:=tt*number[p];
      end;
  end;

 end;
function can:boolean;
 begin
  can:=true;
  if (s[i] in ['+','-']) and (symbol[p]<>'(') then exit;
  if (s[i] in ['*','/']) and (symbol[p] in ['^','%']) then exit;
  if (s[i] in ['^','%']) and (symbol[p] in ['^']) then exit;
  if (s[i] in ['%']) and (symbol[p] in ['%']) then exit;
  can:=false;
 end;

function isRight(tr:string):boolean;
 var a:array [1..max] of char;
     pp:integer;
begin
 case tr[1] of
  '+','-','*','/','^','%',')':
  begin
    isRight:=false;
       showmessage('第一个字符不能为运算符，请确认后重新输入！');
    exit;
  end;
 end;
 for pp:=1 to length(tr)-1 do
  begin
   case tr[pp] of
    '+','-','*','/','^','%':
     begin
      case
       tr[pp+1] of
        '+','-','*','/','^','%':
         begin
          isRight:=false;
             showmessage('符号不能叠加，请确认后重新输入！');
          exit
         end;
      end;
     end;
   end;
  end;
  isRight:=true;
end;


procedure TForm1.Button3Click(Sender: TObject);
begin
 form1.Close;
end;

procedure TForm1.Button1Click(Sender: TObject);
var error:integer;
begin
 flag:=true;
 button2.Visible:=true;
 label2.Visible:=true;
 edit2.Visible:=true;
 listbox1.Visible:=true;
 listbox1.Clear;
 s:=edit1.Text ;
 //edit1.Enabled:=false;
 while not(isRight(s)) do
  begin
  button2.Visible:=false;
   edit1.Text:='0';
   s:=edit1.Text;
  end;
 count:=1;
  s:='('+s+')'; i:=1; p:=0;
while i<=length(s) do
begin
 while s[i]='(' do
  begin
   push; inc(i);
  end;
 j:=i;
 repeat
 inc(i);
 until ((s[i]<'0') or (s[i]>'9'));
 t:=copy(s,j,i-j);
 val(t,number[p],code);
 inc(count);
 repeat
 if s[i]=')' then
  begin
   while symbol[p]<>'(' do pop;
    dec(p); number[p]:=number[p+1];
   end
 else
  begin
   error:=1;
   while can do
   begin
    pop;
     if flag=false then
      begin
       edit1.Text:='0';
       button2.Visible:=false;
       exit;
      end;
     inc(error);
    if error>3 then
     begin
      showmessage('您的输入中括号搭配有问题！请确认后重输！');
      button2.Visible:=false;
      edit1.Text:='0';
      exit;

     end;
   end;
    push;
  end;
 inc(i);
 until (i>length(s)) or (s[i-1]<>')');
end;
 edit2.Text:=inttostr(number[0]);
end;

procedure TForm1.Button2Click(Sender: TObject);
 var error:integer;
begin
button2.Visible:=false;
//edit1.Enabled:=true;
for i:=0 to max do
  number[i]:=0;
for i:=1 to max do
  symbol[i]:=' ';
s:=edit1.Text ;
 count:=1;
  s:='('+s+')'; i:=1; p:=0;
  tr:='第'+inttostr(count)+'步:变字符串为:'+s;
  listbox1.AddItem(tr,listbox1);
while i<=length(s) do
begin
 while s[i]='(' do
  begin
   push; tr:='第'+inttostr(count)+'步:符号'+s[i]+'入符号栈,此时符号栈内容为:';
   listbox1.AddItem(tr,listbox1);
   for kk:=0 to p do
   begin
     tr:=symbol[kk]+' ';
     listbox1.AddItem(tr,listbox1);
   end;
    inc(i);
  end;
 j:=i;
 repeat
 inc(i);
 until ((s[i]<'0') or (s[i]>'9'));
 t:=copy(s,j,i-j);
 val(t,number[p],code);
 inc(count);
  tr:='第'+inttostr(count)+'步:把数据'+t+'压入数据栈.数据栈内容为:';
  listbox1.AddItem(tr,listbox1);
  for kk:=0 to p do
   begin
    tr:=inttostr(number[kk])+' ';
     listbox1.AddItem(tr,listbox1);
   end;
 repeat
 if s[i]=')' then
  begin
   while symbol[p]<>'(' do pop;
    dec(p); number[p]:=number[p+1];
      tr:='第'+inttostr(count)+'步:数据栈阶段处理,数据栈内容为:';
      listbox1.AddItem(tr,listbox1);
      for kk:=0 to p do
   begin
    tr:=inttostr(number[kk])+' ';
     listbox1.AddItem(tr,listbox1);
   end;
   end
 else
  begin
   error:=1;
   while can do
    begin
     pop;
     tr:='第'+inttostr(count)+'步:开始取操作数做'+symbol[p+1]+'运算,数据栈内容为:';
   listbox1.AddItem(tr,listbox1);
   for kk:=0 to p do
   begin
    tr:=inttostr(number[kk])+' ';
     listbox1.AddItem(tr,listbox1);
   end;

    end;
    push;  tr:='第'+inttostr(count)+'步:符号'+s[i]+'入符号栈,此时符号栈内容为:';
   listbox1.AddItem(tr,listbox1);
   for kk:=0 to p do
   begin
     tr:=symbol[kk]+' ';
     listbox1.AddItem(tr,listbox1);
   end;
  end;
 inc(i);
 until (i>length(s)) or (s[i-1]<>')');
end;
 edit2.Text:=inttostr(number[0]);

end;

procedure TForm1.FormShow(Sender: TObject);
begin
 for i:=0 to max do
  number[i]:=0;
  button2.Visible:=false;
  label2.Visible:=false;
  edit2.Visible:=false;
  listbox1.Visible:=false;
  mm:=0;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
 mm:=mm+1;
 case mm mod 7 of
  0:label3.Font.Color:=clblue;
  1:label3.font.Color:=clred;
  2:label3.font.Color:=clyellow;
  3:label3.font.Color:=clgreen;
  4:label3.font.Color:=clpurple;
  5:label3.font.Color:=clblack;
  6:label3.font.Color:=clwhite;
 end;
end;

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
 case key of
  '+','-','*','/','%','^','(',')',#8:exit;
  '0'..'9':exit;
  end;
    key:=#0;
    showmessage('为了程序的正常运行，非法字符已锁定，抱歉！');
end;

end.