Compilare: user.cpp: In function ‘int get_nr()’: user.cpp:10:13: warning: suggest parentheses around comparison in operand of ‘|’ [-Wparentheses] while(c < 48 | c > 57) c = getchar(); ^ user.cpp:12:14: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] while (c > 47 & c < 58) ^ user.cpp: In function ‘int main()’: user.cpp:23:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("exp.in", "r", stdin); ^ user.cpp:24:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("exp.out", "w", stdout); ^