Compilare: main.cpp: In function 'void add(std::__cxx11::string)': main.cpp:34:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < word.size(); i++) ~~^~~~~~~~~~~~~ main.cpp: In function 'void del(std::__cxx11::string)': main.cpp:51:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < word.size(); i++) ~~^~~~~~~~~~~~~ main.cpp: In function 'void printApps(std::__cxx11::string)': main.cpp:64:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < word.size(); i++) ~~^~~~~~~~~~~~~ main.cpp: In function 'void printLen(std::__cxx11::string)': main.cpp:82:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < word.size(); i++) ~~^~~~~~~~~~~~~