Compilare: user.cpp: In function ‘int main()’: user.cpp:20:19: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if (s[i] >= 'a' && s[i] <= 'z' || s[i] >= 'A' && s[i] <= 'Z') ^ user.cpp:13:35: 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:14:37: 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:16:26: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(s, 1, MAXN, stdin); ^