foo.cc: In function 'int main()':
foo.cc:7:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
7 | for(int i=0;i<s.size() ;i++)
| ~^~~~~~~~~
foo.cc:10:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
10 | for(int j=0;j<s.size() ;j++)
| ~^~~~~~~~~
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