AcWing 831. KMP字符串

#include <iostream>
#include <stdio.h>
#include <string>
using namespace std;
const int N = 100010, M = 1000010;
char p[N], s[M];
int n,m;
int ne[N];
int main(){
    cin >> n >> p + 1 >> m >> s + 1;
    //next
    for(int i = 2,j = 0; i <= n; i ++){
        while(j && p[i] != p[j + 1]) j = ne[j];
        if(p[i] == p[j+1]) j++;
        ne[i] = j;
    }
    for(int i = 1, j = 0; i <= m; i ++ ){
        while(j && s[i] != p[j + 1]) j = ne[j];
        if(s[i] == p[j + 1]) j++;
        if(j == n){
            //success
            cout << i - n << ' ';
            j = ne[j];
        }
    }
    return 0;
}