存程序

program aaa;
type point=record
     c:array[1..26] of longint;
     cover:longint;
    end;
var n,m,i,k,x,y,o,tmp:longint;
pos1:char;
s:array[0..50000] of char;
t:array[0..200000] of point;
procedure build(p,l,r:longint);
var m,j:longint;
begin
t[p].cover:=0;
 if l=r then 
  begin
   t[p].c[ord(s[l])-64]:=1;
   exit;
  end;
m:=(l+r) shr 1;
build(p*2,l,m);
build(P*2+1,m+1,r);
 for j:=1 to 26 do t[p].c[j]:=t[p*2].c[j]+t[p*2+1].c[j];
end;
procedure change(p,l,r:longint;var px,py,po:longint);
var mid:longint;
begin
  if t[p].cover<>0 then 
    begin
     fillchar(t[p].c,sizeof(t[p].c),0); 
     t[p].c[t[p].cover]:=r-l+1;
     t[2*p].cover:=t[p].cover;
     t[2*p+1].cover:=t[p].cover;
    end;
 if (l>=px) and (r<=py) then 
  begin
   t[p].cover:=po;
   exit;
  end;
mid:=(l+r) shr 1;
 if px<=mid then change(p*2,l,mid,px,py,po);
 if py>mid then change(p*2+1,mid+1,r,px,py,po);
end;
function answer(p,l,r:longint;var px,py,po:longint):longint;
var mid,xs:longint;
begin
 if t[p].cover<>0 then 
    begin
     fillchar(t[p].c,sizeof(t[p].c),0); 
     t[p].c[t[p].cover]:=r-l+1;
     t[2*p].cover:=t[p].cover;
     t[2*p+1].cover:=t[p].cover;
    end;
 if (l=px) and (r=py) then exit(t[p].c[po]);
mid:=(l+r) shr 1;
 if py<=mid then exit(answer(p*2,l,mid,px,py,po));
 if px>mid then exit(answer(P*2+1,mid+1,r,px,py,po));
xs:=mid+1;
 if (px<=mid) and (py>mid) then exit(answer(p*2,l,mid,px,mid,po)+answer(P*2+1,mid+1,r,xs,py,po));
end;
procedure sort(p,l,r:longint;var px,py:longint);
begin
end;
begin
readln(n,m);
 for i:=1 to n do
  begin
   read(s[i]);
   if (s[i]<='z') and (s[i]>='a') then s[i]:=chr(ord(s[i])-32);
  end;
build(1,1,n);   
 for i:=1 to m do
  begin
   read(o);
   if o=1 then
    begin       
    read(x,y,pos1);
    while pos1=' ' do read(pos1);
    readln;
    tmp:=ord(pos1)-64;
    writeln(pos1);
    writeln(answer(1,1,n,x,y,tmp));
    end;
   if o=2 then 
    begin
     read(x,y,pos1);
     while pos1=' ' do read(pos1);
     readln;
     tmp:=ord(pos1)-64;
     change(1,1,n,x,y,tmp);
    end;
   if o=3 then
    begin
     readln(x,y);  
     sort(1,1,n,x,y);
    end;
  end; 
end.