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Just treat the Nested List as a tree, and dfs it: private int sum =0; public int depthSum(List<NestedInteger> nestedList) { helper(nestedList, 1); ret 阅读全文
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The simplest way that I can think to solve this problem is using a PriorityQueue: public int[][] kClosest(int[][] points, int k) { PriorityQueue<int[] 阅读全文
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For example, if the int[] w ={3,14,1,7}, we can make a presum array based on it: int[] presums = {3, 17, 18, 25} We using Ramdom's nextInt() to genera 阅读全文
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This problem can be solved by using the solution of 236. Lowest Common Ancestor of a Binary Tree. While the tree here is a binary search tree, so the 阅读全文
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This problem is just as same as "235. Lowest Common Ancestor of a Binary Search Tree", the only difference is, 235 is two points, 1676 is 1~n points. 阅读全文
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The first solution of this problem can be based on the 236. Lowest Common Ancestor of a Binary Tree too: public Node lowestCommonAncestor(Node p, Node 阅读全文
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When we get this problem, we need to confirm the following 2 questions: 1. Can root, p or q be null? (No) 2. Are both p and q in the tree (No, either 阅读全文
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When we get this problem, we need to confirm the following 3 questions: 1. Can root, p or q be null? (No) 2. Are both p and q in the tree (yes) 3. Can 阅读全文
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Although this is an easy question, but it is prone to bugs, and the code can be better. Following is my first solution, didn't use the feature of BST. 阅读全文
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For sparse venctors, there might be too many "0"s in the array. What we need to do is only abstract the items which are not "0". We store these non-ze 阅读全文
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My first solution is use two skacks, one stack store index, another one store value, the time complexity is O(n). public int[] findBuildings(int[] hei 阅读全文