Compilare: user.cpp: In function ‘int main()’: user.cpp:16:20: warning: unused variable ‘x1’ [-Wunused-variable] int i,j,x,y,NR,x1,y1; ^ user.cpp:16:23: warning: unused variable ‘y1’ [-Wunused-variable] int i,j,x,y,NR,x1,y1; ^ user.cpp:13:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("betasah.in", "r", stdin); ^ user.cpp:14:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("betasah.out", "w", stdout); ^ user.cpp:18:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); scanf("%d%d",&D,&K); ^ user.cpp:18:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); scanf("%d%d",&D,&K); ^ user.cpp:28:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {scanf("%d%d",&x,&y); A[x][y]=1;} ^ user.cpp:31:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {scanf("%d%d",&x,&y); A[x][y]=0;} ^