Compilare: user.cpp: In function ‘int main()’: user.cpp:7:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rfinv.in","r",stdin); ^ user.cpp:8:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rfinv.out","w",stdout); ^ user.cpp:10:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ user.cpp:12:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:14:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&v[i].first,&v[i].second); ^ user.cpp:17:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] d[i][j]=2000000000,scanf("%d",&a[i][j]); ^ user.cpp:33:12: warning: ‘j’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (i==n+1 && j==n+1) ^