Compilare: user.cpp: In function ‘int main()’: user.cpp:40:13: warning: unused variable ‘l’ [-Wunused-variable] int l=(temp.x-1)*n+temp.y; ^ user.cpp:15:15: warning: unused variable ‘i’ [-Wunused-variable] int m,n,k,i,j; ^ user.cpp:13:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("castel.in","r",stdin); ^ user.cpp:14:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("castel.out","w",stdout); ^ user.cpp:16:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&m,&n,&k); ^ user.cpp:19:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i][j]); ^