不需要那么麻烦

#include <iostream>
#include <queue>
using namespace std;
bool vis[100010];
queue<long long> q;
long long d[100010];
long long a[3] = {-1 , 1 };
int main ()
{
    long long n , k , t , x;
    cin >> n >> k;
    q.push (n);
    vis[n] = 1;
    while (!q.empty())
    {
        t = q.front ();
        q.pop();
        if (t == k)
        {
            cout << d[t] << endl;
            return 0;
        }
        a[2] = t;
        for (long long i = 0 ; i < 3 ; i ++)
        {
            x = t + a[i];
            if (x >=0 && x <= 100000 && !vis[x])
            {
                d[x] = d[t] + 1;
                vis[x] = 1;
                q.push (x);
            }
        }
    }
    return 0;
}