ac1020.pas

某牛人写的acm.tongji.edu.cn上大部分ac的代码,仅供学习研究,请不要用来作弊

program tju1020;
var
  n,i,p:byte;
  s:string;
  a,b,c:char;
begin
  readln(n);
  for i:=1 to n do begin
    readln(s);
    read(a);
    case a of
      'D':begin
            readln(b,b);
            p:=pos(b,s);
            if p=0 then
              writeln('error')
            else begin
              delete(s,p,1);
              writeln(s);
            end;
          end;
      'I':begin
            readln(b,b,c,c);
            for p:=length(s) downto 0 do
              if p=0 then
                writeln('error')
              else
                if s[p]=b then begin
                  insert(c,s,p);
                  writeln(s);
                  break;
                end;
          end;
      'R':begin
            readln(b,b,c,c);
            for p:=1 to length(s) do
              if s[p]=b then s[p]:=c;
            writeln(s);
          end;
    end;
  end;
end.