0394-decode-string.adoc

394. Decode String

{leetcode}/problems/decode-string/[LeetCode - Decode String^]

Given an encoded string, return its 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 positive integer.

You may assume that the input string is always valid; No extra white spaces, square brackets are well-formed, etc.

Furthermore, you may assume that the original data does not contain any digits and that digits are only for those repeat numbers, k. For example, there won’t be input like 3a or 2[4].

Examples:

s = "3[a]2[bc]", return "aaabcbc".
s = "3[a2[c]]", return "accaccacc".
s = "2[abc]3[cd]ef", return "abcabccdcdcdef".

思路分析

主要就是一个栈操作。不过，还需要注意一些细节。

一刷

link:{sourcedir}/_0394_DecodeString.java[role=include]

二刷

link:{sourcedir}/_0394_DecodeString_2.java[role=include]

参考资料

1. 394. 字符串解码 - 辅助栈法 / 递归法，清晰图解

2. 394. 字符串解码 - 附详细图解例子，清晰易懂