Compilare: user.cpp: In function ‘void solve(int)’: user.cpp:37: warning: comparison between signed and unsigned integer expressions user.cpp:39: warning: comparison between signed and unsigned integer expressions user.cpp:51: warning: comparison between signed and unsigned integer expressions user.cpp:86: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:140: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:141: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:142: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:145: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result