Compilare: user.cpp: In function ‘int main()’: user.cpp:8:9: warning: unused variable ‘n’ [-Wunused-variable] int n,i,j,x,y,nr=0; ^ user.cpp:6:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen("magicnum.in", "r",stdin); ^ user.cpp:7:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("magicnum.out", "w",stdout); ^ user.cpp:15:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^