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回溯算法 阅读全文
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本题要采用 回溯法 来解决 阅读全文
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本题目可以采用三种方法Straightforward DFS recursive, iterative, BFS solutions 1.深度优先 递归 2.迭代 3.广度优先 a.要弄懂final关键字的含义 此题不加也行 b.迭代 c.广度优先 阅读全文
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动态规划，注意处理当前最大值小于0的情况 阅读全文
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根部到叶子节点路径之和为某值，递归 阅读全文
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递归，注意结果的三重判断 阅读全文
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The basic idea is that, for example, nums = [1,2,3,4,5,6,7] and k = 3, first we reverse [1,2,3,4,5,6,7], it becomes[7,6,5,4,3,2,1]; then we reverse[7, 阅读全文
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Given two binary trees, write a function to check if they are equal or not. Two binary trees are considered equal if they are structurally identical a 阅读全文
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Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array. Note:You may assume that nums1 has enough space (size tha 阅读全文
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Given a sorted linked list, delete all duplicates such that each element appear only once. For example,Given 1->1->2, return 1->2.Given 1->1->2->3->3, 阅读全文