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Count Binary Substrings (E) 题目 Give a string s, count the number of non-empty (contiguous) substrings that have the same number of 0's and 1's, and al 阅读全文
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Brick Wall (M) 题目 There is a brick wall in front of you. The wall is rectangular and has several rows of bricks. The bricks have the same height but d 阅读全文
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Triangle (M) 题目 Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below. For examp 阅读全文
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N-ary Tree Preorder Traversal (E) 题目 Given the root of an n-ary tree, return the preorder traversal of its nodes' values. Nary-Tree input serializatio 阅读全文
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Combination Sum IV (M) 题目 Given an array of distinct integers nums and a target integer target, return the number of possible combinations that add up 阅读全文
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Number of Submatrices That Sum to Target (H) 题目 Given a matrix and a target, return the number of non-empty submatrices that sum to target. A submatri 阅读全文
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Remove All Adjacent Duplicates in String II (M) 题目 Given a string s, a k duplicate removal consists of choosing k adjacent and equal letters from s an 阅读全文
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Fibonacci Number (E) 题目 The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum 阅读全文
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Partition List (M) 题目 Given a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x. Yo 阅读全文
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Beautiful Arrangement II (M) 题目 Given two integers n and k, you need to construct a list which contains n different positive integers ranging from 1 t 阅读全文