Compilare: user.cpp: In function ‘void readData()’: user.cpp:45:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &M); ^ user.cpp:47:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int a, b; scanf("%d%d", &a, &b); ^ user.cpp:52:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int a, b; scanf("%d%d", &a, &b); ^