Compilare: user.cpp: In function ‘void df(int)’: user.cpp:55: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void df2(int)’: user.cpp:94: warning: comparison between signed and unsigned integer expressions user.cpp:97: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:115: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:116: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:122: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp: In function ‘void df(int)’: user.cpp:53: warning: ‘fmax’ may be used uninitialized in this function