Compilare: user.cpp: In function ‘int main()’: user.cpp:39:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i<strlen(s)) ^ user.cpp:41:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (s[i]<'a' || s[i]>'z' && i<strlen(s)) ^ user.cpp:41:37: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while (s[i]<'a' || s[i]>'z' && i<strlen(s)) ^ user.cpp:52:52: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (s[i]>='a' && s[i]<='z' && i<strlen(s)) ^