标签归档：leetcode

题目描述：

LeetCode 424. Longest Repeating Character Replacement

Given a string that consists of only uppercase English letters, you can replace any letter in the string with another letter at most k times. Find the length of a longest substring containing ...

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LeetCode 423. Reconstruct Original Digits from English

Given a non-empty string containing an out-of-order English representation of digits 0-9, output the digits in ascending order.

Note:

1. Input contains only lowercase English letters.
2. Input is guaranteed to be valid and ...

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LeetCode 422. Valid Word Square

Given a sequence of words, check whether it forms a valid word square.

A sequence of words forms a valid word square if the k^th row and column read the exact same string ...

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LeetCode 421. Maximum XOR of Two Numbers in an Array

Given a list of numbers, a[0], a[1], a[2], … , a[N-1], where 0 <= a[i] < 2^32. Find the maximum result of a[i ...

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LeetCode 419. Battleships in a board

Given an 2D board, count how many different battleships are in it. The battleships are represented with 'X's, empty slots are represented with '.'s. You may assume the following rules ...