【小米oj】纯位数

时间复杂度本人没有证明，但是暴力交上去过了

#define mm(a) memset(a,0,sizeof(a));
#define max(x,y) (x)>(y)?(x):(y)
#define min(x,y) (x)<(y)?(x):(y)
#define Fopen freopen("1.in","r",stdin); freopen("m.out","w",stdout);
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,b,a) for(int i=(b);i>=(a);i--)
#include<bits/stdc++.h>
typedef long long ll;
#define PII pair<ll,ll>
using namespace std;
const int INF=0x3f3f3f3f;
const int MAXN=(int)2e5 + 5;
const ll mod=10000019;
int n;
bool ck(int x)
{
    int now=n;
    int temp=now%x;
    now/=x;
    while(now){
        if(now%x!=temp)return 0;
        now/=x;
    }
    return 1;
}
int main()
{
    scanf("%d",&n);
    for(int i=2;i<=n+1;i++){
        if(ck(i))return printf("%d
",i),0;
    }
    return 0;
}