Compilare: main.cpp: In function 'int main()': main.cpp:8:6: warning: unused variable 'i' [-Wunused-variable] {int i; ^ main.cpp:9:7: warning: unused variable 'ok' [-Wunused-variable] bool ok = 0; ^~ main.cpp:16:42: warning: 't' may be used uninitialized in this function [-Wmaybe-uninitialized] if((t >= 'a' && t <= 'z') || (t >= 'A' && t <= 'Z')) ~~~~~~~~~~^~~~~~~~~~~~