/in/foo.cc: In function 'void insert()':
/in/foo.cc:24:9: warning: unused variable 'j' [-Wunused-variable]
  int i, j, now = 0,len=strlen(s2);
         ^
/in/foo.cc: In function 'double query()':
/in/foo.cc:37:9: warning: unused variable 'j' [-Wunused-variable]
  int i, j, now = 0;
         ^