Compilare: user.cpp: In function ‘int main()’: user.cpp:12:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s.length()) ^ user.cpp:14:21: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(s[i]>='a'&&s[i]<='z' || (s[i]>='A' && s[i]<='Z')) ^ user.cpp:22:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s.length() && (s[i]>='a'&&s[i]<='z') || (s[i]>='A' && s[i]<='Z')); ^ user.cpp:22:32: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while(i<s.length() && (s[i]>='a'&&s[i]<='z') || (s[i]>='A' && s[i]<='Z')); ^