Compilare: user.cpp: In function ‘int main()’: user.cpp:39:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bila.in","r",stdin); ^ user.cpp:40:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bila.out","w",stdout); ^ user.cpp:42:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:45:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i][j]); ^ user.cpp: In function ‘void back(int, int)’: user.cpp:31:22: warning: ‘y’ may be used uninitialized in this function [-Wmaybe-uninitialized] back(x,y); ^ user.cpp:31:22: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized]