Borderou de evaluare (job #164656)

Compilare: user.cpp: In function ‘int valid(int)’: user.cpp:9:116: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] user.cpp: In function ‘void back(int)’: user.cpp:23:11: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] user.cpp: In function ‘int main()’: user.cpp:36:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] user.cpp:37:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] user.cpp:38:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] user.cpp:40:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]