智商太低了
详细题解在这里http://blog.csdn.net/zmoiynlp/article/details/45176129
1 const max=50001; 2 var u,c,p:array[0..max] of longint; 3 g:array[0..max] of int64; 4 v:array[0..max] of boolean; 5 i,j,t,n,m:longint; 6 7 function min(a,b:longint):longint; 8 begin 9 if a>b then exit(b) else exit(a); 10 end; 11 12 function cal(n,m:longint):int64; 13 var i,j:longint; 14 begin 15 i:=1; 16 cal:=0; 17 while i<=min(n,m) do 18 begin 19 j:=min(n div (n div i), m div (m div i)); 20 cal:=cal+int64(u[j]-u[i-1])*g[n div i]*g[m div i]; 21 i:=j+1; 22 end; 23 end; 24 25 begin 26 u[1]:=1; 27 g[1]:=1; 28 c[1]:=1; 29 for i:=2 to max do 30 begin 31 if not v[i] then 32 begin 33 inc(t); 34 p[t]:=i; 35 g[i]:=2; 36 c[i]:=1; 37 u[i]:=-1; 38 end; 39 for j:=1 to t do 40 begin 41 if i*p[j]>max then break; 42 v[i*p[j]]:=true; 43 if i mod p[j]=0 then 44 begin 45 g[i*p[j]]:=g[i] div (c[i]+1)*int64(c[i]+2); 46 c[i*p[j]]:=c[i]+1; 47 u[i*p[j]]:=0; 48 break; 49 end; 50 g[i*p[j]]:=g[i]*2; 51 u[i*p[j]]:=-u[i]; 52 c[i*p[j]]:=1; 53 end; 54 end; 55 for i:=1 to max do 56 begin 57 u[i]:=u[i-1]+u[i]; 58 g[i]:=g[i-1]+g[i]; 59 end; 60 readln(t); 61 while t>0 do 62 begin 63 dec(t); 64 readln(n,m); 65 writeln(cal(n,m)); 66 end; 67 end.
