Compilare: user.c: In function ‘litera’: user.c:4:15: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if('A'<=k && k<='Z' || 'a'<=k && k<='z') ^ user.c: In function ‘main’: user.c:4:15: warning: ‘kv’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.c:16:13: note: ‘kv’ was declared here char k, kv; ^