Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:23: error: ‘abs’ was not declared in this scope user.cpp:28: warning: comparison between signed and unsigned integer expressions user.cpp:32: error: ‘abs’ was not declared in this scope user.cpp:37: error: ‘abs’ was not declared in this scope user.cpp:18: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:20: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result