438. Find All Anagrams in a String

static int wing=[]()
{
    std::ios::sync_with_stdio(false);
    cin.tie(NULL);
    return 0;
}();

class Solution 
{
public:
    vector<int> findAnagrams(string s, string p) 
    {   
        vector<int>res;
        int lens=s.length();
        int lenp=p.length();
        if(lens<lenp)
            return res;
        vector<int> sv(26,0);
        vector<int> pv(26,0);
        for(char c:p)
            pv[c-'a']++;
        int max=lens-lenp+1;
        for(int i=0;i<lenp;i++)
            sv[s[i]-'a']++;
        if(sv==pv)
            res.push_back(0);
        int i=0,j=lenp-1;
        while(i<max-1)
        {     
            sv[s[i++]-'a']--;
            sv[s[++j]-'a']++;    
            if(sv==pv)
                res.push_back(i);
        }
        return res;
    }
};

用滑动窗口，移动判定