Compilare: user.cpp: In function ‘int main()’: user.cpp:79:152: warning: integer overflow in expression [-Woverflow] std::vector < std::vector < std::vector < int > > > mat(n + 2, std::vector< std::vector < int > > (n + 2, std::vector < int > ( n + 2, (1 << 31) - 1 ))); ^ user.cpp:72:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alge.in", "r", stdin); ^ user.cpp:73:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alge.out", "w", stdout); ^ user.cpp:77:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &ng); ^ user.cpp:90:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&x, &y, &z, &lg); ^