1 Uses Math;
  2 Var
  3   a,b:AnsiSTring;
  4   DC,la,lb:longint;
  5   c:Array[-2555555..2555555] of longint;
  6 Procedure Plus(a,b:AnsiSTring);
  7   Var
  8     Tt,i:longint;
  9   Begin
 10     if la>lb Then
 11       Begin
 12         For i:=1 to la-lb do
 13           b:='0'+b;
 14         lb:=la;
 15       End
 16     Else
 17       Begin
 18         For i:=1 to lb-la do
 19           a:='0'+a;
 20         la:=lb;
 21       End;
 22     For i:=1 to la do
 23       c[i]:=Ord(a[i])+Ord(b[i])-96;
 24     For i:=la Downto 1 do
 25       if (c[i]+DC)>=10 Then
 26         Begin
 27           Tt:=(c[i]+DC) Mod 10;
 28           DC:=(c[i]+DC) Div 10;
 29           c[i]:=Tt;
 30         End
 31       Else
 32         Begin
 33           c[i]:=c[i]+DC;
 34           DC:=0;
 35         End;
 36     c[0]:=-1;
 37     if DC>0 Then c[0]:=DC;
 38     For i:=0 to la do
 39       if c[i]<>-1 Then  Write(c[i]);
 40     Writeln;
 41   End;
 42 Procedure Minus(A,b:AnsiSTring);
 43   Var
 44     t:AnsiSTring;
 45     Tt,i:longint;
 46   Begin
 47     if la>=lb Then
 48       Begin
 49         For i:=1 to la-lb do
 50           b:='0'+b;
 51         lb:=la;
 52       End
 53     Else
 54       Begin
 55         For i:=1 to lb-la do
 56           a:='0'+a;
 57         la:=lb;
 58         Write('-');
 59         t:=a;
 60         a:=b;
 61         b:=t;
 62       End;
 63     For i:=1 to la do
 64       c[i]:=Ord(a[i])-Ord(b[i]);
 65     For i:=la Downto 1 do
 66       if (c[i])<0 Then
 67         Begin
 68           c[i]:=c[i]+10;
 69           c[i-1]:=c[i-1]-1;
 70         End;
 71     lb:=1;
 72     While (c[lb]=0) And (lb<la) do Inc(lb);
 73     For i:=lb to la do
 74       if c[i]<>-1 Then  Write(c[i]);
 75     Writeln;
 76   End;
 77 Procedure Multiply(a,b:AnsiString);
 78   Var
 79     Tt,xx,i,j:longint;
 80   Begin
 81     xx:=0; Tt:=Maxlongint;
 82     For i:=La Downto 1 do
 83       For j:=lb Downto 1 do
 84         Begin
 85           c[i+j-1]:=((Ord(a[i])-48)*(Ord(b[j])-48)+c[i+j-1]);
 86           Tt:=Min(Tt,i+j-1);
 87           xx:=Max(xx,i+j-1);
 88         End;
 89     While c[tt]=0 Do Inc(tt);
 90     DC:=0;
 91     For i:=xx Downto Tt Do
 92       Begin
 93         if c[i]+DC>=10 Then
 94           Begin
 95             lb:=c[i];
 96             c[i]:=(c[i]+DC) Mod 10;
 97             DC:=(lb+DC) Div 10;
 98           End
 99         Else                           //17956
100           Begin
101             c[i]:=c[i]+Dc;
102             DC:=0;
103           End;
104       End;
105     if DC>0 Then Write(DC);
106     For i:=Tt To xx do Write(c[i]); Writeln;
107   End;
108 Begin
109   While True Do
110     Begin
111       Writeln('高精度数字计算器 Ver 0.9 Done By Catch-22.S.In');
112       Writeln('本计算器暂时只支持加减乘三则运算,其他运算更新中...');
113       Writeln('请不要拿无聊的超多位数来BS本程序，谢谢合作.');
114       Writeln('请输入要计算的两个高精度数字:');
115       Write('请输入第一个数字，并换行:');
116       Readln(a);
117       Write('请输入第二个数字，并换行:');
118       Readln(b);
119       la:=length(a);
120       lb:=Length(b);
121       Writeln('计算中..');
122       FillChar(c,Sizeof(c),0); DC:=0;
123       Write(a,'+',b,'=');
124       Plus(a,b);
125       FillChar(c,Sizeof(c),0); DC:=0;
126       Write(a,'-',b,'=');
127       Minus(a,b);
128       FillChar(c,Sizeof(c),0); DC:=0;
129       Write(a,'*',b,'=');
130       Multiply(a,b);
131       Writeln('谢谢使用，如需继续计算请输入11,如不需要请输入任意字符');
132       Readln(a);
133       if a<>'11' Then
134          Begin
135            Writeln('Thank You.');
136            For la:=1 to Maxlongint Shr 4 do lb:=1;
137            Exit;
138          End;
139     End;
140 End.