Compilare: user.cpp: In function ‘void read()’: user.cpp:18:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &N, &M, &L); ^ user.cpp:19:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=1; i<=N; i++) scanf("%d", &A[i]); ^ user.cpp:20:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=1; i<=M; i++) scanf("%d", &B[i]); ^ user.cpp: In function ‘int main()’: user.cpp:60:24: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(inf,"r",stdin); freopen(outf,"w",stdout); ^ user.cpp:60:50: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(inf,"r",stdin); freopen(outf,"w",stdout); ^