bzoj3994

智商太低了

详细题解在这里http://blog.csdn.net/zmoiynlp/article/details/45176129

const max=50001;
var u,c,p:array[0..max] of longint;
    g:array[0..max] of int64;
    v:array[0..max] of boolean;
    i,j,t,n,m:longint;

function min(a,b:longint):longint;
  begin
    if a>b then exit(b) else exit(a);
  end;

function cal(n,m:longint):int64;
  var i,j:longint;
  begin
    i:=1;
    cal:=0;
    while i<=min(n,m) do
    begin
      j:=min(n div (n div i), m div (m div i));
      cal:=cal+int64(u[j]-u[i-1])*g[n div i]*g[m div i];
      i:=j+1;
    end;
  end;

begin
  u[1]:=1;
  g[1]:=1;
  c[1]:=1;
  for i:=2 to max do
  begin
    if not v[i] then
    begin
      inc(t);
      p[t]:=i;
      g[i]:=2;
      c[i]:=1;
      u[i]:=-1;
    end;
    for j:=1 to t do
    begin
      if i*p[j]>max then break;
      v[i*p[j]]:=true;
      if i mod p[j]=0 then
      begin
        g[i*p[j]]:=g[i] div (c[i]+1)*int64(c[i]+2);
        c[i*p[j]]:=c[i]+1;
        u[i*p[j]]:=0;
        break;
      end;
      g[i*p[j]]:=g[i]*2;
      u[i*p[j]]:=-u[i];
      c[i*p[j]]:=1;
    end;
  end;
  for i:=1 to max do
  begin
    u[i]:=u[i-1]+u[i];
    g[i]:=g[i-1]+g[i];
  end;
  readln(t);
  while t>0 do
  begin
    dec(t);
    readln(n,m);
    writeln(cal(n,m));
  end;
end.