2299 - L1097 的题解
回去原题# a,b,c:array[0..200000] of longint;
procedure kp(l,r:longint);
var i,j,mid,t:longint;
begin
i:=l;j:=r;mid:=a[(l+r) div 2];
repeat
while a[i]<mid do inc(i);
while a[j]>mid do dec(j);
if i<=j then begin
t:=a[i];a[i]:=a[j];a[j]:=t;
inc(i);dec(j);
end;
until i>j;
if l<j then kp(l,j);
if i<r then kp(i,r);
end;
begin
readln(n);
for i:=1 to n do readln(a[i]);
kp(1,n);
for i:=1 to n do begin
if a[i]<>x then begin
x:=a[i];inc(w);b[w]:=a[i];c[w]:=1;
end else inc(c[w]);
end;
for i:=1 to w do writeln(b[i],' ',c[i]);
end.