Compilare: user.cpp:25:43: warning: multi-character character constant [-Wmultichar] if(s[i] >= ' ' && s[i] <= '?' && i != 'NULL') ^ user.cpp: In function ‘int main()’: user.cpp:21:20: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(s[i] >= 'A' && s[i] <= 'Z' || s[i] >= 'a' && s[i] <= 'z') ^ user.cpp:13:14: warning: unused variable ‘sir’ [-Wunused-variable] char s[100],sir[100]; ^ user.cpp:10:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("text.in", "r", stdin); ^ user.cpp:11:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("text.out", "w", stdout); ^ user.cpp:15:22: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s, 100, stdin); ^