Compilare: user.cpp: In function ‘int main()’: user.cpp:61:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("vis.in","r",stdin); ^ user.cpp:62:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("vis.out","w",stdout); ^ user.cpp:64:70: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d %d %d %d\n", &N, &K1, &K2, &L1, &C1, &L2, &C2); ^ user.cpp:71:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &Mat[i][j]); ^