Tin học - Bài 51: Thay thế từ

Bài 51/2001 - Thay thế từ
(Dành cho học sinh THCS và PTTH)
program thaythetu;
var
 source,des:array[1..50]of string;
 n:byte;
procedure init;
var
 i:byte;
 s:string;
 f:text;
begin
 assign(f,'input2.txt');
 reset(f);
 n:=0;
 while not eof(f) do
 begin
 readln(f,s);
 inc(n);
 while (s'')and(s[1]=' ') do
 delete(s,1,1);
 if i>0 then
 begin
 i:=pos(' ',s);
 des[n]:=copy(s,1,i-1);
 while (i<=length(s))and(s[i]=' ') do
 i:=i+1;
 source[n]:=copy(s,i,length(s)-i+1);
 end;
 end;
end;
procedure replace;
var
 f,g:text;
 s:string;
 i,k:byte;
begin
 assign(f,'input1.txt');
 reset(f);
 assign(g,'kq.out');
 rewrite(g);
 while not eof(f) do
 begin
 readln(f,s);
 for k:=1 to n do
 for i:=1 to length(s)-length(des[k])+1 do
 if des[k]=copy(s,i,length(des[k])) then
 begin
 delete(s,i,length(des[k]));
 insert(source[k],s,i);
 i:=i+length(source[k]);
 end;
 writeln(g,s);
 end;
 close(f);
 close(g);
end;
begin
 init;
 replace;
end.