Compilare: user.cpp: In function ‘int main()’: user.cpp:10:15: warning: unused variable ‘j’ [-Wunused-variable] int t,n,i,j,k,x; ^ user.cpp:10:17: warning: unused variable ‘k’ [-Wunused-variable] int t,n,i,j,k,x; ^ user.cpp:10:19: warning: unused variable ‘x’ [-Wunused-variable] int t,n,i,j,k,x; ^ user.cpp:14:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("perechi3.in","r",stdin); ^ user.cpp:15:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("perechi3.out","w",stdout); ^ user.cpp:34:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ user.cpp:37:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^