Make writing a habit together! This is the 7th day of my participation in the “Gold Digging Day New Plan · April More text Challenge”. Click here for more details.

Topic describes

This is 796 on LeetCode. Rotate string, easy difficulty.

Tag: “Simulation”

Given two strings, S and goal. Returns true if s can become goal after a number of rotation operations.

The rotation operation of S moves the leftmost character of S to the right.

  • For example, if thes = 'abcde'After one rotation, the result is going to be'bcdea' 。

Example 1:

Input: s = "abcde", goal = "cdeab" Output: trueCopy the code

Example 2:

Input: s = "abcde", goal = "abced" Output: falseCopy the code

Tip:


  • 1 < = s . l e n g t h . g o a l . l e n g t h < = 100 1 <= s.length, goal.length <= 100
  • s 和 goalConsists of lowercase English letters

simulation

Because each rotation operation moves the leftmost character to the right, if GOAL can be derived from S through multiple steps of rotation, then goal must appear in S + S, which satisfies (S + S). Contains (goal). At the same time, in order to hold the result caused by s itself being too long, We need to make sure that the two strings are the same length.

Code:

class Solution {
    public boolean rotateString(String s, String goal) {
        returns.length() == goal.length() && (s + s).contains(goal); }}Copy the code
  • Time complexity: O(n)O(n)O(n)
  • Space complexity: O(n)O(n)O(n)

The last

This is the No.796 of our “Brush through LeetCode” series, which started on 2021/01/01. There are 1916 topics on LeetCode as of the start date, some of which have locks.

In this series of articles, in addition to explaining how to solve the problem, I will also present the most concise code possible. If a general solution is involved, the corresponding code template will also be used.

In order to facilitate the students to debug and submit the code on the computer, I set up the relevant warehouse: github.com/SharingSour… .

In the repository, you’ll see links to the series of articles, the corresponding code for the series of articles, the LeetCode source links, and other preferred solutions.