Compilare: user.cpp: In function ‘int main()’: user.cpp:15:9: warning: unused variable ‘l’ [-Wunused-variable] int l,i,j,jj,ii,q,sf1,inc1,sf2,inc2; ^ user.cpp:15:15: warning: unused variable ‘jj’ [-Wunused-variable] int l,i,j,jj,ii,q,sf1,inc1,sf2,inc2; ^ user.cpp:15:18: warning: unused variable ‘ii’ [-Wunused-variable] int l,i,j,jj,ii,q,sf1,inc1,sf2,inc2; ^ user.cpp:15:21: warning: unused variable ‘q’ [-Wunused-variable] int l,i,j,jj,ii,q,sf1,inc1,sf2,inc2; ^ user.cpp:12:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("collar.in","r",stdin); ^ user.cpp:13:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("collar.out","w",stdout); ^ user.cpp:18:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); ^ user.cpp:19:46: 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]); ^