Compilare: user.cpp: In function ‘void backtracking(int, int, int)’: user.cpp:16:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘int main()’: user.cpp:31:9: warning: unused variable ‘i’ [-Wunused-variable] int i,j; ^ user.cpp:31:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp:29:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bilete.in","r",stdin); ^ user.cpp:30:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bilete.out","w",stdout); ^ user.cpp:32:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^