acdream1116 Gao the string!(扩展KMP)

#pragma warning(disable:4996)
#include <iostream>
#include <cstring>
#include <string>
#include <vector>
#include <cmath>
#include <cstdio>
#include <algorithm>
using namespace std;

#define ll long long
#define mxs 1000000 
#define mxt 100000
#define mod 1000000007

char s[mxs], t[mxt];

int nxt[mxt], ex[mxt];

// get the next array for t only
void getNext(char *t,int *nxt)
{
	int m = strlen(t);
	nxt[0] = m;
	int j = 0;
	while (j + 1 < m&&t[j] == t[j + 1]) j++;
	nxt[1] = j;
	int k = 1; int p, L;
	for (int i = 2; i < m; i++)
	{
		p = nxt[k] + k - 1;
		L = nxt[i - k];
		if (i + L < p + 1) nxt[i] = L; // i+L<=p
		else
		{
			j = max(0, p - i + 1);
			while (i + j < m&&t[i + j] == t[0 + j])j++;
			nxt[i] = j;
			k = i;
		}
	}
}

// get the next array for t, and get the ex array for s;
void getExtend(char *s, char *t, int *nxt, int *ex)
{
	getNext(t, nxt);
	int n = strlen(s), m = strlen(t);
	int j = 0;
	while (j < n&&j < m&&s[j] == t[j]) j++;
	ex[0] = j;
	int k = 0; int p, L;
	for (int i = 1; i < n; i++){
		p = ex[k] + k - 1;
		L = nxt[i - k];
		if (i + L < p + 1) ex[i] = L;
		else{
			j = max(0, p - i + 1);
			while (i + j < n&&j < m&&s[i + j] == t[j]) j++;
			ex[i] = j;
			k = i;
		}
	}
}

struct Matrix
{
	ll a[2][2];
	Matrix(){ memset(a, 0, sizeof(a)); }
}m;

Matrix operator * (const Matrix &a, const Matrix &b){
	Matrix ret;
	for (int i = 0; i < 2; i++){
		for (int j = 0; j < 2; j++){
			for (int k = 0; k < 2; k++){
				ret.a[i][j] += (a.a[i][k] * b.a[k][j]) % mod;
				ret.a[i][j] %= mod;
			}
		}
	}
	return ret;
}
Matrix operator ^ (Matrix a, ll n){
	Matrix ret;
	for (int i = 0; i < 2; i++) ret.a[i][i] = 1;
	while (n){
		if (n & 1) ret = ret*a;
		n >>= 1;
		a = a*a;
	}
	return ret;
}

ll cal(ll n)
{
	m.a[0][0] = 0; m.a[0][1] = 1;
	m.a[1][0] = 1; m.a[1][1] = 1;
	m = m^n;
	return m.a[0][1];
}

int main()
{
	while (~scanf("%s",s)){
		getNext(s, nxt);
		int n = strlen(s);
		nxt[n] = 0;
		ll ans = 0;
		for (int i = n - 1; i >= 0; i--){
			nxt[i] += nxt[i + 1];
			ans += cal(nxt[i]);
			ans %= mod;
		}
		printf("%lld\n", ans);
	}
	return 0;
}