Compilare: user.cpp: In function ‘void read()’: user.cpp:27:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&N,&M); ^ user.cpp:29:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",a[i]+1); ^ user.cpp: In function ‘int main()’: user.cpp:124:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("barbar.in","r",stdin); ^ user.cpp:125:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("barbar.out","w",stdout); ^