Compilare: user.cpp: In function ‘int main()’: user.cpp:39:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,n,m,k; ^ user.cpp:41:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d %d",&n,&m,&k); ^ user.cpp:42:44: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d %d %d",&l1,&c1,&l2,&c2); ^ user.cpp:47:38: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&a[i],&b[i]); ^