地址 https://www.luogu.com.cn/problem/P3375
解法
KMP模板
#include<iostream>
#include<cstring>
using namespace std;
const int N = 1000010, M = 1000010;
int n, m;
int ne[N];
char s[M], p[N];
int main()
{
std::cin >> (s + 1) >> (p + 1);
int m = strlen(s+1);
int n = strlen(p + 1);
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)
{
std::cout << i - n + 1 << std::endl;
j = ne[j];
}
}
for (int i = 1; i <= n; i++) {
std::cout << ne[i] << " ";
}
return 0;
}