foo.cc: In function 'int Search(std::string&, char)':
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.length();i++)
      |                     ~^~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:20:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |    for(int i=0;i<s.length();i++)
      |                ~^~~~~~~~~~~
foo.cc:20:4: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   20 |    for(int i=0;i<s.length();i++)
      |    ^~~
foo.cc:22:5: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   22 |     float fre=100.0*num/s.length();
      |     ^~~~~

[Hydro](https://hydro.ac)提供评测服务