/in/foo.cc: In function 'int main()':
/in/foo.cc:97:20: warning: 'ul' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if (!temp) printf("%d ",ul+q*m);  
              ~~~~~~^~~~~~~~~~~~~~
/in/foo.cc:52:5: warning: 'ul' may be used uninitialized in this function [-Wmaybe-uninitialized]
   ul+=q*(i-1);//此后b，c含义换了 
   ~~^~~~~~~~~