Compilare: user.cpp: In function ‘int main()’: user.cpp:19:19: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if ( s[i]>='a' && s[i]<='z' || 'A'<=s[i] && s[i]<='Z'){ ^ user.cpp:21:22: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] for (; s[i]>='a' && s[i]<='z' || 'A'<=s[i] && s[i]<='Z';++i); ^