摘要： Daxinganling produces a lot of timber. Before loading onto trains, the timberjacks will place the logs to some place in the open air first. Looking from the sideway, the figure of a logs stack is as follows: We have known that the number of logs in each layer is fewer than the lower layer for at least one log, and that in each layer the logs are connected in a line. In the figure above, the 阅读全文