{ "data": { "question": { "questionId": "2520", "questionFrontendId": "2434", "categoryTitle": "Algorithms", "boundTopicId": 1874039, "title": "Using a Robot to Print the Lexicographically Smallest String", "titleSlug": "using-a-robot-to-print-the-lexicographically-smallest-string", "content": "

You are given a string s and a robot that currently holds an empty string t. Apply one of the following operations until s and t are both empty:

\n\n\n\n

Return the lexicographically smallest string that can be written on the paper.

\n\n

 

\n

Example 1:

\n\n
\nInput: s = "zza"\nOutput: "azz"\nExplanation: Let p denote the written string.\nInitially p="", s="zza", t="".\nPerform first operation three times p="", s="", t="zza".\nPerform second operation three times p="azz", s="", t="".\n
\n\n

Example 2:

\n\n
\nInput: s = "bac"\nOutput: "abc"\nExplanation: Let p denote the written string.\nPerform first operation twice p="", s="c", t="ba". \nPerform second operation twice p="ab", s="c", t="". \nPerform first operation p="ab", s="", t="c". \nPerform second operation p="abc", s="", t="".\n
\n\n

Example 3:

\n\n
\nInput: s = "bdda"\nOutput: "addb"\nExplanation: Let p denote the written string.\nInitially p="", s="bdda", t="".\nPerform first operation four times p="", s="", t="bdda".\nPerform second operation four times p="addb", s="", t="".\n
\n\n

 

\n

Constraints:

\n\n\n", "translatedTitle": "使用机器人打印字典序最小的字符串", "translatedContent": "

给你一个字符串 s 和一个机器人，机器人当前有一个空字符串 t 。执行以下操作之一，直到 s 和 t 都变成空字符串：

\n\n\n\n

请你返回纸上能写出的字典序最小的字符串。

\n\n

 

\n\n

示例 1：

\n\n
输入：s = \"zza\"\n输出：\"azz\"\n解释：用 p 表示写出来的字符串。\n一开始，p=\"\" ，s=\"zza\" ，t=\"\" 。\n执行第一个操作三次，得到 p=\"\" ，s=\"\" ，t=\"zza\" 。\n执行第二个操作三次，得到 p=\"azz\" ，s=\"\" ，t=\"\" 。\n
\n\n

示例 2：

\n\n
输入：s = \"bac\"\n输出：\"abc\"\n解释：用 p 表示写出来的字符串。\n执行第一个操作两次，得到 p=\"\" ，s=\"c\" ，t=\"ba\" 。\n执行第二个操作两次，得到 p=\"ab\" ，s=\"c\" ，t=\"\" 。\n执行第一个操作，得到 p=\"ab\" ，s=\"\" ，t=\"c\" 。\n执行第二个操作，得到 p=\"abc\" ，s=\"\" ，t=\"\" 。\n
\n\n

示例 3：

\n\n
输入：s = \"bdda\"\n输出：\"addb\"\n解释：用 p 表示写出来的字符串。\n一开始，p=\"\" ，s=\"bdda\" ，t=\"\" 。\n执行第一个操作四次，得到 p=\"\" ，s=\"\" ，t=\"bdda\" 。\n执行第二个操作四次，得到 p=\"addb\" ，s=\"\" ，t=\"\" 。\n
\n\n

 

\n\n

提示：

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