foo.cc: In function 'void built()':
foo.cc:16:18: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   16 |     for(int i=0;i<strlen(str1);i++)
      |                 ~^~~~~~~~~~~~~
foo.cc: In function 'int query()':
foo.cc:30:17: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   30 |    for(int i=0;i<strlen(str1);i++)
      |                ~^~~~~~~~~~~~~

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