Compilare: user.cpp: In function ‘int main()’: user.cpp:64:13: warning: unused variable ‘r’ [-Wunused-variable] int l=0,r=2000000000; ^ user.cpp:50:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("slidingwindow.in","r",stdin); ^ user.cpp:51:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("slidingwindow.out","w",stdout); ^ user.cpp:54:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&d); ^ user.cpp:58:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ",&a[i].v); ^