【leetcode】438. Find All Anagrams in a String

2022-02-02 17:31:07 阅读：214 来源： 互联网

标签：index ab letters String Anagrams substring start anagram leetcode

Given two strings s and p, return an array of all the start indices of p's anagrams in s. You may return the answer in any order.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

Example 1:

Input: s = "cbaebabacd", p = "abc"
Output: [0,6]
Explanation:
The substring with start index = 0 is "cba", which is an anagram of "abc".
The substring with start index = 6 is "bac", which is an anagram of "abc".

Example 2:

Input: s = "abab", p = "ab"
Output: [0,1,2]
Explanation:
The substring with start index = 0 is "ab", which is an anagram of "ab".
The substring with start index = 1 is "ba", which is an anagram of "ab".
The substring with start index = 2 is "ab", which is an anagram of "ab".

Constraints:

1 <= s.length, p.length <= 3 * 10⁴
s and p consist of lowercase English letters.

利用hash表进行比较，只要包含的相同的子序列字符即可，然后利用滑动窗口进行比较。

class Solution {
public:
    vector<int> findAnagrams(string s, string p) {
        // 如何拆解string p 构成需要匹配的anagrams
        // 变位词只要保证存在这个词即可 不需要顺序 利用hash表进行对比
        vector<int> vecRes={};
        int nLs=s.size();
        int nLp=p.size();
        if(nLs<nLp) return vecRes;
        // 两个hash表 进行存储
        vector<int> vecPoint(26,0),vecSlide(26,0);
        for(int i=0;i<nLp;++i){
            vecPoint[p[i]-'a']+=1;
            vecSlide[s[i]-'a']+=1;
        }
        if(vecPoint==vecSlide){
            vecRes.push_back(0);
        }
        int index=0;
        for(index;index<nLs-nLp;index++){
            //cout<<index<<endl; 
            // move this slide window
            vecSlide[s[index]-'a']-=1;
            vecSlide[s[index+nLp]-'a']+=1;
            if(vecPoint==vecSlide){
                vecRes.push_back(index+1);
            }
        }
        return vecRes;
        
    }
};

标签：index,ab,letters,String,Anagrams,substring,start,anagram,leetcode
来源： https://www.cnblogs.com/aalan/p/15860532.html

本站声明： 1. iCode9 技术分享网（下文简称本站）提供的所有内容，仅供技术学习、探讨和分享；
2. 关于本站的所有留言、评论、转载及引用，纯属内容发起人的个人观点，与本站观点和立场无关；
3. 关于本站的所有言论和文字，纯属内容发起人的个人观点，与本站观点和立场无关；
4. 本站文章均是网友提供，不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属；如您发现该文章侵犯了您的权益，可联系我们第一时间进行删除；
5. 本站为非盈利性的个人网站，所有内容不会用来进行牟利，也不会利用任何形式的广告来间接获益，纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。

ICode9

【leetcode】438. Find All Anagrams in a String