算法思路出处

搞懂算法思路后，代码相较于朴素的kmp更易理解

#include <bits/stdc++.h>

using namespace std;

string s , p ;
int n , m ;

int main()
{
    cin >> n >> p >> m >> s ;
    string str = p + '#' + s ; 
    vector<int > pi(str.size()) ;

    for (int i = 1 ; i < str.size() ; i ++)
    {
        int len = pi[i - 1];
        while (len && str[i] != str[len]) len = pi[len - 1] ;

        if (str[i] == str[len])
        {
            pi[i] = len + 1 ;
            if (pi[i] == n) cout << i - n * 2 << ' ' ;
        }
    }

    return 0 ;
}