/in/foo.cc: In function 'int main()':
/in/foo.cc:16:10: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
    j=1<<d-1;
         ~^~
/in/foo.cc:22:29: warning: right operand of comma operator has no effect [-Wunused-value]
   d=(int)log2(r[i]-l[i]+1),j<<d;
                            ~^~~
/in/foo.cc:23:40: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized]
   cout<<max(premax[l[i]][d],premax[r[i]-j+1][d])<<"\n"; 
                                    ~~~~^~