Compilare: user.cpp: In function ‘int get_nr()’: user.cpp:7:13: warning: suggest parentheses around comparison in operand of ‘|’ [-Wparentheses] for(; c < 48 | c > 57; c = getchar()); ^ user.cpp:9:13: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] for(; c > 47 & c < 58; nr = nr * 10 + c - 48, c = getchar()); ^ user.cpp: In function ‘int main()’: user.cpp:16:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sticle.in", "r", stdin); ^ user.cpp:17:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sticle.out", "w", stdout); ^