Compilare: main.cpp: In function 'void solve()': main.cpp:71:19: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 71 | if(-1+s.size()==k) | ~~~~~~~~~~~^~~ main.cpp: At global scope: main.cpp:92:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] 92 | main() | ^~~~ main.cpp: In function 'int main()': main.cpp:94:10: warning: variable 'sol' set but not used [-Wunused-but-set-variable] 94 | auto sol=[&](bool x) | ^~~