Compilare: main.cpp: In function 'void divide(int, int)': main.cpp:69:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<s.size();i++) ~^~~~~~~~~ main.cpp:25:9: warning: unused variable 'k' [-Wunused-variable] int k = 0, ok = 1; ^ main.cpp:25:16: warning: variable 'ok' set but not used [-Wunused-but-set-variable] int k = 0, ok = 1; ^~