Compilare: user.cpp: In function ‘void write()’: user.cpp:99:21: warning: unused variable ‘level’ [-Wunused-variable] int x, y, buss, level; ^ user.cpp:100:10: warning: unused variable ‘ok’ [-Wunused-variable] bool ok = true; ^ user.cpp: In function ‘void read()’: user.cpp:30:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ user.cpp:33:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &c); ^ user.cpp: In function ‘int main()’: user.cpp:138:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &T); ^