摘要：
A family hierarchy is usually presented by a pedigree tree. Your job is to count those family members who have no child. Input Each input file contain 阅读全文
摘要：
A supply chain is a network of retailers（零售商）, distributors（经销商）, and suppliers（供应商）-- everyone involved in moving a product from supplier to customer 阅读全文
摘要：
A family hierarchy is usually presented by a pedigree tree where all the nodes on the same level belong to the same generation. Your task is to find t 阅读全文