数据结构：KMP

题目描述

输入样例

3
abc
9
abcabcabc

输出样例

0 3 6 

参考代码

#include <iostream>

using namespace std;

const int N = 10010, M = 100010;

int n, m;
char p[N], s[N];
int ne[N];

int main()
{
    cin >> n >> p + 1 >> m >> s + 1;
    
    // 求next过程
    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;
    }
    
    // kmp 匹配过程
    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)
        {
            // 匹配成功
            printf("%d ", i - n);
            j = ne[j];
        }
    }
    return 0;
}