Compilare: main.cpp: In function 'int main()': main.cpp:8:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sir.in","r",stdin); ^ main.cpp:9:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sir.out","w",stdout); ^ main.cpp:10:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&x,&y,&z); ^ main.cpp:11:42: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(i=1; i<=n; i++) scanf("%d",&a[i]); ^