foo.cc: In function 'int main()':
foo.cc:7:15: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
    7 |  for(int i=0;i<strlen(a) ;i++)
      |              ~^~~~~~~~~~
foo.cc:10:15: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   10 |  for(int i=1;i<=strlen(a) ;i++)
      |              ~^~~~~~~~~~~
foo.cc:12:15: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   12 |  for(int i=1;i<=strlen(a) ;i++)
      |              ~^~~~~~~~~~~

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