Compilare: user.cpp: In function ‘int main()’: user.cpp:100:9: warning: unused variable ‘j’ [-Wunused-variable] ull i, j, x; ^ user.cpp:100:12: warning: unused variable ‘x’ [-Wunused-variable] ull i, j, x; ^ user.cpp: In function ‘void reading()’: user.cpp:45:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%llu %llu %llu", &N, &M, &K); ^ user.cpp:50:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%llu", &x); ^ user.cpp:57:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%llu %llu %llu", &x, &y, &z); ^ user.cpp: In function ‘int main()’: user.cpp:104:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("catun.in", "r", stdin); ^ user.cpp:105:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("catun.out", "w", stdout); ^