/in/foo.cc: In function 'int main()':
/in/foo.cc:57:23: warning: value computed is not used [-Wunused-value]
     if(d=='Q')  sum(r)-sum(l-1);
                 ~~~~~~^~~~~~~~~
/in/foo.cc:55:10: warning: unused variable 'C' [-Wunused-variable]
     char C;
          ^
/in/foo.cc:57:5: warning: 'd' is used uninitialized in this function [-Wuninitialized]
     if(d=='Q')  sum(r)-sum(l-1);
     ^~