twoheads

摘要： path-sum （1过） Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals th 阅读全文

摘要： best-time-to-buy-and-sell-stock-i Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted t 阅读全文