分析：f(x)和x是相关联的，枚举其中一个，通过计算得到另一个，再判断时候合法即可. 因为f(x)最多只有81,枚举f(x)即可.

#include 
     
      #include 
      
       #include 
       
        #include 
        
         using namespace std;typedef long long ll;const int maxn = 110;int T;ll a,b,c,k,ans,anss[maxn],tot;ll check(ll x){    ll res = 0;    while (x)    {        res += x % 10;        x /= 10;    }    return res;}ll qpow(ll a,ll b){    ll res = 1;    while (b)    {        if (b & 1)            res *= a;        a *= a;        b >>= 1;    }    return res;}int main(){    //freopen("test.txt","r",stdin);    //freopen("safe.out","w",stdout);    scanf("%d",&T);    while (T--)    {        ans = 0;        tot = 0;        scanf("%lld%lld%lld%lld",&a,&b,&c,&k);        for (ll i = 0; i <= 81; i++)        {            ll temp = qpow(i,a) * b + c;            if (temp >= 0 && temp <= k)            {                if (check(temp) == i)                {                    ans++;                    anss[++tot] = temp;                }            }        }        if (ans == 0)            printf("0\n-1\n");        else        {            sort(anss + 1,anss + 1 + tot);            printf("%lld\n",ans);            for (int i = 1; i <= tot; i++)                printf("%lld ",anss[i]);            printf("\n");        }    }    return 0;}