POJ 1207(3N+1)

3n+1问题 果断暴力

Program P1207;var   i,j,k,n,m,ans:longint;function max(a,b:longint):longint;begin   if a>b then exit(a) else exit(b);end;procedure swap(var a,b:longint);var   p:longint;begin   p:=a;   a:=b;   b:=p;end;begin   while not eof do   begin      readln(n,m);      write(n,' ',m,' ');      if n>m then swap(n,m);      ans:=0;      for i:=n to m do      begin         j:=1;         k:=i;         while (k<>1) do         begin            if (k mod 2=0) then k:=k div 2            else k:=k*3+1;            inc(j);         end;         ans:=max(ans,j);      end;      writeln(ans);   end;end.