[acm/icpc2016SEERC][CodeforcesGym101164] Castle KMP

相当于结尾单点插入，单点打标记，查询该字符串所有border的标记和。KMP维护border，转移的时候把标记和一起转移就好
原串border的border还是原串border
O(n)扫一遍就行

#include 
#define N 13000000
using namespace std;
char s[N],ns[10];
bool vis[N];
int p[N],F[N],n,E,j;

inline int rd() {
    int x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}

int main() {
    n = rd(), E = rd();
    scanf("%s",s+1);
    j = 0; p[1] = 0;
    for (int i=2;i<=n;i++) {
        while (j && s[j+1] != s[i]) j = p[j];
        if (s[j+1] == s[i]) j++;
        p[i] = j;
    }

    while (E--) {
        int cmd = rd();
        if (cmd == 1) {
            scanf("%s",ns+1);
            s[++n] = ns[1];
            while (j && s[j+1] != s[n]) j = p[j];
            if (s[j+1] == s[n]) j++;
            p[n] = j;
            F[n] = F[j];
        }
        if (cmd == 2) !vis[n] ? F[n]++, vis[n]=1 :0;
        if (cmd == 3) printf("%d\n",F[n]);
    }
    return 0;
}