Ich bitte um eure Hilfe. 参考https://www.docin.com/p-1172255459.html模拟

#include <bits/stdc++.h>

using namespace std;
#define ULL unsigned long long
deque<ULL> tmp;
ULL A, B, N;
void zz(ULL a, ULL b)
{
    if (a < b)
    {
        swap(a,b);
    }
    int r0,a0;
    r0 = a % b;
    if(r0 == 0){
        return;
    }
    a0 = (a - r0) / b; 
    tmp.push_front(a0);
    zz(b,r0);
    return;
}

int main()
{
    bool flag = false;
    cin >> A >> N;
    zz(A,N);
    ULL b0 = 1;
    ULL b1 = tmp.front();
    ULL bn = tmp.front() * b1 + b0;
    tmp.pop_front();
    if(tmp.size() % 2 == 0){
        flag = true;
    }
    while(tmp.size()){
        bn = tmp.front() * b1 + b0;
        tmp.pop_front();
        b0 = b1;
        b1 = bn;
        //cout << bn << " ";
    }
    if(flag){
        bn = N - bn;
    }
    cout << bn << endl;
    return 0;
}