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Eva loves to collect coins from all over the universe, including some other planets like Mars. One day she visited a universal shopping mall which cou 阅读全文
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The "eight queens puzzle" is the problem of placing eight chess queens on an 8×8 chessboard so that no two queens threaten each other. Thus, a solutio 阅读全文
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Shopping in Mars is quite a different experience. The Mars people pay by chained diamonds. Each diamond has a value (in Mars dollars M\$). When making 阅读全文
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Suppose that all the keys in a binary tree are distinct positive integers. Given the postorder and inorder traversal sequences, you are supposed to ou 阅读全文
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Suppose that all the keys in a binary tree are distinct positive integers. A unique binary tree can be determined by a given pair of postorder and ino 阅读全文
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The following is from Max Howell @twitter: Google: 90% of our engineers use the software you wrote (Homebrew), but you can't invert a binary tree on a 阅读全文
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给定一个三角形，找出自顶向下的最小路径和。每一步只能移动到下一行中相邻的结点上。 例如，给定三角形： 自顶向下的最小路径和为 11（即，2 + 3 + 5 + 1 = 11）。 说明： 如果你可以只使用 O(n) 的额外空间（n 为三角形的总行数）来解决这个问题，那么你的算法会很加分。 dp1[i] 阅读全文