Compilare: user.cpp: In function ‘std::vector<int, std::allocator<int> > merge(std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >)’: user.cpp:121: warning: comparison between signed and unsigned integer expressions user.cpp:121: warning: comparison between signed and unsigned integer expressions user.cpp:134: warning: comparison between signed and unsigned integer expressions user.cpp:139: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:160: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:161: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:162: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:163: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:166: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:179: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:182: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:190: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:191: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:192: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result