P2437 蜜蜂路线

// Problem: P2437 蜜蜂路线
// Contest: Luogu
// URL: https://www.luogu.com.cn/problem/P2437
// Memory Limit: 125 MB
// Time Limit: 1000 ms
// User: Pannnn

#include <bits/stdc++.h>

using namespace std;

template<class T>
void debugVector(const T &a) {
    cout << "[ ";
    for (size_t i = 0; i < a.size(); ++i) {
        cout << a[i] << (i == a.size() - 1 ? " " : ", ");
    }
    cout << "]" << endl;
}

template<class T>
using matrix2 = vector<vector<T>>;

template<class T>
vector<vector<T>> getMatrix2(size_t n, size_t m, T init = T()) {
    return vector<vector<T>>(n, vector<T>(m, init));
}

template<class T>
using matrix3 = vector<vector<vector<T>>>;

template<class T>
vector<vector<vector<T>>> getMatrix3(size_t x, size_t y, size_t z, T init = T()) {
    return vector<vector<vector<T>>>(x, vector<vector<T>>(y, vector<T>(z, init)));
}

void printBigInteger(vector<int> a) {
    for (int i = a.size() - 1; i >= 0; --i) {
        cout << a[i];
    }
}
vector<int> add(vector<int> a, vector<int> b) {
    vector<int> res;
    int pre = 0;
    for (int i = 0; i < a.size() || i < b.size() || pre; ++i) {
        if (i < a.size()) pre += a[i];
        if (i < b.size()) pre += b[i];
        res.push_back(pre % 10);
        pre /= 10;
    }
    return res;
}


int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    /*
        3可从1，2移动到
        4可从2，3移动到
        斐波那契
    */
    int m, n;
    cin >> m >> n;
    vector<vector<int>> info(n + 1, vector<int>());
    
    info[m].push_back(1);
    for (int i = m + 1; i <= n; ++i) {
        info[i] = add(info[i - 1], info[i - 2]);
    }
    printBigInteger(info[n]);
    cout << endl;
    return 0;
}