Compilare: user.cpp: In function ‘int main()’: user.cpp:25:13: warning: unused variable ‘nr’ [-Wunused-variable] int n,i,nr,j,cj; ^~ user.cpp:25:16: warning: unused variable ‘j’ [-Wunused-variable] int n,i,nr,j,cj; ^ user.cpp:25:18: warning: unused variable ‘cj’ [-Wunused-variable] int n,i,nr,j,cj; ^~ user.cpp:23:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("prim.in","r",stdin); ^ user.cpp:24:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("prim.out","w",stdout); ^ user.cpp:26:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^