高精度加法的优化

 1 var
 2  s1,s2:string;
 3 procedure plus(s1,s2:string);
 4 var
 5  a,b,c:array[1..500]of longint;
 6  i,j1,j2,l,k,p,code:longint;
 7 begin
 8  fillchar(a,sizeof(a),0);
 9  fillchar(b,sizeof(b),0);
10  fillchar(c,sizeof(c),0);
11  j1:=0; l:=length(s1);
12  while l>0 do
13  begin
14   inc(j1);
15   val(copy(s1,l-3,4),a[j1],code);
16   s1:=copy(s1,1,l-4); l:=length(s1);
17  end;
18  j2:=0; l:=length(s2);
19  while l>0 do
20  begin
21   inc(j2);
22   val(copy(s2,l-3,4),b[j2],code);
23   s2:=copy(s2,1,l-4); l:=length(s2);
24  end;
25  if j1>j2 then p:=j1 else p:=j2;
26  k:=0;
27 for i:=1 to p do
28  begin
29   c[i]:=a[i]+b[i]+k;
30   k:=c[i] div 10000;
31   c[i]:=c[i] mod 10000;
32  end;
33  if k=1 then
34  begin
35   inc(p); inc(c[p]);
36  end;
37  write(c[p]);
38  for i:=p-1 downto 1 do
39  begin
40   if c[i]<10 then write(‘000‘,c[i]) else
41   if c[i]<100 then write(‘00‘,c[i]) else
42   if c[i]<1000 then write(‘0‘,c[i]) else
43   write(c[i]);
44  end;
45  writeln;
46 end;
47 begin
48  readln(s1);
49  readln(s2);
50  plus(s1,s2);
51 end.