[BOI2009]Radio Transmission 无线传输 - 洛谷https://www.luogu.com.cn/problem/P4391
#include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <cstring>
#include <set>
#include <unordered_map>
#include <cmath>
#include <map>
#include <cctype>
#include <cstdlib>
#include <deque>
typedef long long ll;
typedef unsigned long long ull;
using namespace std;
const int MN = 65005;
const int MAXN = 1e6 + 5;
const int INF = 0x3f3f3f3f;
#define IOS ios::sync_with_stdio(false)
#define lowbit(x) ((x)&(-x))
int n;
char s[MAXN];
int p[MAXN];
int main() {
scanf("%d", &n);
scanf("%s", s + 1);
for (int i = 2, j = 0; i <= n; i++) {
while (j && s[j + 1] != s[i])
j = p[j];
if (s[j + 1] == s[i])
j++;
p[i] = j;
}
printf("%d", n - p[n]);
return 0;
}
