Monday, April 26, 2021

Print All Topology Sort

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Link 本体是二流就（alien dictionary)。很快秒了，但是追加是输出所有topological sort的组合。卡在这了， 我当时的思路是 DFS preprocessing 每一个字母可以 reach 的 set ，做 permutation ， reachab...

Number of Ways Fully Traverse a Matrix

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Link 4、一个4*5迷宫里，给定起点终点和障碍，有多少种方法能够从起点走到终点，并把所有的非障碍点都走过。最开始是四个方向，然后问如果八个方向怎么办 ，如果是国际象棋皇后怎么办   第四题给的数据规模很小，是不是就是dfs暴力就可以了？ 嗨，楼主，最后一题有步数限制嘛？如果没...

Range product (Binary Index Tree)

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 arr = [1,2,3,4,5,6,7]. return the sub array product [i, j]. https://iq.opengenus.org/fenwick-tree-range-product/ 1 2 3 4 5 6 7 8 ...
Thursday, April 15, 2021

LeetCode [1448] Count Good Nodes in Binary Tree

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  1448.   Count Good Nodes in Binary Tree Medium 661 32 Add to List Share Given a binary tree  root , a node  X  in the tree is named  good ...
Saturday, April 3, 2021

LeetCode [938] Range Sum of BST

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  938.   Range Sum of BST Easy 2214 289 Add to List Share Given the  root  node of a binary search tree, return  the sum of values of all no...
Friday, April 2, 2021

LeetCode [1570] Dot Product of Two Sparse Vectors

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  1570.   Dot Product of Two Sparse Vectors Medium 235 38 Add to List Share Given two sparse vectors, compute their dot product. Implement c...