Compilare: user.cpp: In function ‘int main()’: user.cpp:13:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<strlen(s);i++){ ^ user.cpp:16:103: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (;((65<=int(s[i]) and int(s[i])<=90)or(97<=int(s[i]) and int(s[i])<=122)and i<strlen(s));i++) ^ user.cpp:16:89: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] for (;((65<=int(s[i]) and int(s[i])<=90)or(97<=int(s[i]) and int(s[i])<=122)and i<strlen(s));i++) ^