Compilare: user.cpp: In function ‘int right_son(int)’: user.cpp:18: warning: suggest parentheses around ‘+’ inside ‘>>’ user.cpp: In function ‘void sift(int)’: user.cpp:40: warning: comparison between signed and unsigned integer expressions user.cpp:43: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:96: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:97: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:98: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:101: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:103: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result