Compilare: main.cpp:34:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] main() ^ main.cpp: In function 'int main()': main.cpp:91:23: warning: unused variable 'ok' [-Wunused-variable] int ok = true; ^~ main.cpp:123:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l.size(); i++) ~~^~~~~~~~~~ main.cpp:117:13: warning: unused variable 'timer' [-Wunused-variable] int timer = 0; ^~~~~