foo.cc: In function 'int main()':
foo.cc:15:34: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   15 |                         for(i=0;i<strlen(s);i++)
      |                                 ~^~~~~~~~~~
foo.cc:20:42: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   20 |                                 for(j=i;j<strlen(s);j++)
      |                                         ~^~~~~~~~~~
foo.cc:51:34: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   51 |                         for(i=0;i<strlen(s);i++)
      |                                 ~^~~~~~~~~~

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