/in/foo.cc: In function 'void cdq(int, int)':
/in/foo.cc:36:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m=l+r>>1;
        ~^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:68:13: warning: unused variable 'k' [-Wunused-variable]
     int i,j,k;
             ^