Compilare: user.c: In function ‘main’: user.c:38:16: warning: initialization from incompatible pointer type [enabled by default] pair *last = root; ^ user.c:31:8: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&T); ^ user.c:33:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&N); ^ user.c:34:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&M); ^ user.c:42:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&x1); ^ user.c:43:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&x2); ^