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Given an array A of 0s and 1s, we may change up to K values from 0 to 1. Return the length of the longest (contiguous) subarray that contains only 1s. 阅读全文
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In an alien language, surprisingly they also use english lowercase letters, but possibly in a different order. The order of the alphabet is some permu 阅读全文
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Given a 01 matrix, find the longest line of consecutive 1 in the matrix. The line could be horizontal, vertical, diagonal or anti-diagonal. Example 1: 阅读全文
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问题一： pi表示取第i个单，di表示送第i个单。di不能在pi的前面。给一个取单送单的顺序，问是否是valid顺序。 1 public boolean isValidOrderList(List<String> list) { 2 Set<String> set = new HashSet<>() 阅读全文
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Google Calendar, Outlook, iCal has been banned from your company! So an intrepid engineer has decided to roll their own implementation. Unfortunately 阅读全文
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Implement a SnapshotArray that supports the following interface: SnapshotArray(int length) initializes an array-like data structure with the given len 阅读全文
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Question: Detect cycle in a directed graph Answer: Depth First Traversal can be used to detect cycle in a Graph. DFS for a connected graph produces a 阅读全文
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Quick Sort: Time complexity: best case O(n*lgn), worst case O(n^2) Space complexity: Best case O(lgn) -> call stack height Worse case O(n^2) -> call s 阅读全文
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Given an undirected graph, return true if and only if it is bipartite. Recall that a graph is bipartite if we can split it's set of nodes into two ind 阅读全文
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Assume you have k<=10^5 intervals [a_i, b_i] \in [1,10^18] (some of them may overlap), and you need to choose a set of intervals mutually disjoint suc 阅读全文