View Compilation Error

0_0_33532973_15279.cpp: In function 'int main()':
0_0_33532973_15279.cpp:18:15: error: cannot convert 'std::string {aka std::basic_string<char>}' to 'const char*' for argument '1' to 'size_t strlen(const char*)'
   len=strlen(s);
               ^