Compilare: user.cpp: In function ‘int main()’: user.cpp:19:27: warning: unused variable ‘ct’ [-Wunused-variable] int n,m,k,q,x,y,i,j,z,ct,lin; ^~ user.cpp:21:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ture.in","r",stdin); ^ user.cpp:22:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ture.out","w",stdout); ^ user.cpp:23:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&m,&k,&q); ^ user.cpp:29:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&y,&x); ^ user.cpp:37:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^