Compilare: main.cpp: In function 'int cost(std::__cxx11::string, std::__cxx11::string)': main.cpp:14:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<=a.size(); i++) ~^~~~~~~~~~ main.cpp:16:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<=b.size(); j++) ~^~~~~~~~~~ main.cpp:18:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<=a.size(); i++) { ~^~~~~~~~~~ main.cpp:19:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1; j<=b.size(); j++) { ~^~~~~~~~~~