Leetcode brush questions [22-day summary] Interview questions 01.09. String rotation

CSDN Topic Challenge Phase 2
Participation Topic: Algorithm Solution

Topic link and description

https://leetcode.cn/problems/string-rotation-lcci/

String rotation. Given two strings s1 and s2, write code to check whether s2 is the rotation of s1 (for example, waterbottle is the rotation of erbottlewat).

Example 1:

Input: s1 = "waterbottle", s2 = "erbottlewat"
Output: True
Example 2:

Input: s1 = "aa", s2 = "aba"
Output: False
Prompt:

The string length is in the range [0, 100000].
illustrate:

Can you call the method that checks the substring only once?

Keywords: splicing and matching kmp algorithm

method one:

run screenshot

the code

    public boolean isFlipedString(String s1, String s2) {
    
    
        if(s1.length()!=s2.length()){
    
    
            return false;
        }
        s1 += s1;
        return s1.contains(s2);
    }

Conclusion

It takes 21 days to form a habit. It has been 23 days since the 7th.

Here is a brief review summary:

• The node paths dfs and bfs of the graph on the first day, by the way, review the related concepts of the graph
• Mock question for the second day, rearranging the spaces between words
• Fast and slow pointer on the third day, regrouped numbers
• The fourth day is also an induction question, beautiful queue
• The fifth day, dynamic programming, the longest fixed difference sequence
• On the sixth day, build a binary tree and review the traversal of the tree
• On the seventh day, beating workers, the lowest cost problem for k people
• Day 8, binary search, array eigenvalues
• Day 9, Greedy Algorithm, Maximum Exchange
• Day 11, truth tables, finding patterns, light bulb switches
• Day 12, first contact scan line, area covered
• Thirteenth day, sliding window, hash table, the longest string between the same characters
• Day 15, matrix, hash table, artificial island
• Day 16, pruning, recursion, finding k equal subsets
• The eighteenth day is also a hash table, whether it can be connected into an array
• On the 20th day, three methods, XOR, summation, in-place hash, seeking to disappear double digits
• The twenty-first day, hash table, reordering, character rearrangement

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