交不成功，记录代码

也供参考

#include<bits/stdc++.h>
using namespace std;
#define int long long
int n;
int s(int n){
	int sum=0;
	while(n){
		sum+=n%10;
		n/=10;
	}
	return sum;
}
int func(int a) {
	if(a*a+s(a)*a==n)return true;
	return false;
}
main() {
	cin >> n;
	int x;
	for (int i = 1; i <= n; ++i) {
		if (func(i)) {
			cout<<i<<endl;
			return 0;
		}
	}
	cout<<"-1"<<endl;
	return 0;
}