Compilare: user.cpp: In function ‘void exec(const char*, const char*)’: user.cpp:51:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file_in,"%d%d",&N,&M); ^ user.cpp:56:48: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file_in,"%d%d%d",&node,&value,&length); ^