L1-103 整数的持续性 分数 20

#include <bits/stdc++.h>
using namespace std;
#define int long long
int func(int n)
{
    int res = 0;
    while(n >= 10)
    {
        int a = n;
        vector<int> num;
        while(a)
        {
            num.push_back(a % 10);
            a /= 10;
        }
        n = 1;
        for(auto ni : num)
            n *= ni;
        ++ res;
    }
    return res;
}
signed main()
{
    int a, b;
    cin >> a >> b;
    int maxi = 0;
    vector<int> ans;
    for(int i = a; i <= b; ++ i)
    {
        if(func(i) > maxi)
        {
        	ans.clear();
			ans.push_back(i);
			maxi = func(i); 
		}
        else if(func(i) == maxi) ans.push_back(i);
    }
    cout << maxi << endl;
    for(auto ai : ans)
    	cout << ai << (ai == ans.back() ? "" : " ");
    return 0;
}