Compilare: main.cpp: In function 'void back(int)': main.cpp:35:11: warning: suggest explicit braces to avoid ambiguous 'else' [-Wdangling-else] 35 | if( OK(k) ) | ^ main.cpp: In function 'int main()': main.cpp:43:9: warning: variable 'cn' set but not used [-Wunused-but-set-variable] 43 | int cn,a,sum=0,k,ok=0; | ^~ main.cpp:43:20: warning: unused variable 'k' [-Wunused-variable] 43 | int cn,a,sum=0,k,ok=0; | ^