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[LeetCode]Permutations
作者是 发布于 在 LeetCode.

题目描述：

LeetCode 46. Permutations

Given a collection of distinct numbers, return all possible permutations.

For example,
[1,2,3] have the following permutations:

[
  [1,2,3],
  [1,3,2],
  [2,1,3],
  [2,3,1],
  [3,1,2],
  [3,2,1]
]

题目大意：

给定一个唯一数字的集合，返回所有可能的排列。

测试用例如题目描述。

解题思路：

递归（Recursion）

记传入数组为nums，若nums的长度不大于1，则直接返回[nums]

遍历nums，从中抽取一个数num，递归计算剩余数字组成的数组n，然后将num与结果合并

Python代码：

class Solution(object):
    def ...

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[LeetCode]Next Permutation
作者是 发布于 在 LeetCode.

题目描述：

LeetCode 31. Next Permutation

Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.

If such arrangement is not possible, it must rearrange it as the lowest possible order (ie, sorted in ascending order).

The ...

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LeetCode Weekly Contest 3解题报告
作者是 发布于 在 LeetCode.

LeetCode Weekly Contest 3是LeetCode举办的第二场正式周赛，共4道题目，比赛时长2.5小时。

比赛链接：https://leetcode.com/contest/leetcode-weekly-contest-3/

题解列表：

LeetCode 392. Is Subsequence

LeetCode 393. UTF-8 Validation

LeetCode 394. Decode String

LeetCode 395. Longest Substring with At Least K Repeating Characters

[LeetCode]Longest Substring with At Least K Repeating Characters
作者是 发布于 在 LeetCode.

题目描述：

LeetCode 395. Longest Substring with At Least K Repeating Characters

Find the length of the longest substring T of a given string (consists of lowercase letters only) such that every character in T appears no less than k times. ...

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[LeetCode]Decode String
作者是 发布于 在 LeetCode.

题目描述：

LeetCode 394. Decode String

Given an encoded string, return it's decoded string.

The encoding rule is: k[encoded_string], where the encoded_string inside the square brackets is being repeated exactly k times. Note that k is guaranteed to be a ...

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