Compilare: main.cpp: In function 'void test_case()': main.cpp:11:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 11 | for(int i = 0;i < str.size(); ++i){ | ~~^~~~~~~~~~~~ main.cpp:26:7: warning: suggest explicit braces to avoid ambiguous 'else' [-Wdangling-else] 26 | if(str[i] == 'x') | ^