Compilare: main.cpp: In function 'int main()': main.cpp:30:10: warning: unused variable 'c1' [-Wunused-variable] 30 | char c1,c2,c3,c4; | ^~ main.cpp:30:13: warning: unused variable 'c2' [-Wunused-variable] 30 | char c1,c2,c3,c4; | ^~ main.cpp:30:16: warning: unused variable 'c3' [-Wunused-variable] 30 | char c1,c2,c3,c4; | ^~ main.cpp:30:19: warning: unused variable 'c4' [-Wunused-variable] 30 | char c1,c2,c3,c4; | ^~