*Leetcode 438. 找到字符串中所有字母异位词

Posted 2023-03-05 Z-Pilgrim

https://leetcode.cn/problems/find-all-anagrams-in-a-string/

思路比较直接 但是细节

class Solution 
public:
    vector<int> findAnagrams(string s, string p) 
        vector<int> use(128, 0);
        int cnt = 0;
        for(int i = 0; i < p.size(); i++)
            if(use[p[i]] == 0) 
                cnt++; 
            
            use[p[i]] ++;
        
            
            
        vector<int>h(128,0);
        int has = 0;
        vector<int> ans;
        for(int i = 0; i < s.size(); i++) 
            if(i - (int)p.size() >= 0) 
                if(use[s[i-p.size()]] && h[s[i-p.size()]] > 0) 
                    if(h[s[i-p.size()]] == use[s[i-p.size()]])has--;
                    h[s[i- p.size()]] --; 
                
            
            if(use[s[i]] ) 
                
                h[s[i]] ++;
                if(h[s[i]] == use[s[i]]) has++;
                
                if(has == cnt) 
                    ans.push_back(i - p.size() + 1);
                 

             
            
            // cout << "i:" << i << " has:" << has << " c:" << s[i] << " cnt:" << cnt << endl;
        
        return ans;
    
;