Codeforces 460B Little Dima and Equation(暴力)

题目链接：Codeforces 460B Little Dima and Equation

题目大意：给定a，b，c，求有多少x满足公式x=b∗s(x)a+c（s(x)为x的各个位数的累加和）

解题思路：枚举，因为x很大，所以直接枚举s(x)。

#include <cstdio>
#include <cstring>
#include <vector>
#include <algorithm>

using namespace std;
typedef long long ll;

int a, b, c;

ll f (int x) {
    ll ret = 1;
    for (int i = 0; i < a; i++)
        ret *= x;
    return ret * b + c;
}

bool judge (int s, int x) {
    int ret = 0;
    while (x) {
        ret += x % 10;
        x /= 10;
    }
    return ret == s;
}

int main () {
    vector<int> vec;
    scanf("%d%d%d", &a, &b, &c);
    for (int i = 1; i <= 81; i++) {
        ll u = f(i);
        if (u < 1e9 && judge(i, u))
            vec.push_back((int)u);
    }

    sort(vec.begin(), vec.end());
    printf("%lu\n", vec.size());
    for (int i = 0; i < vec.size(); i++)
        printf("%d%c", vec[i], i == vec.size() - 1 ? '\n' : ' ');
    return 0;
}