2.15提高组每日一题

[是泡泡]

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double db;
typedef pair<int, int> PII;
#define x first
#define y second
#define ms(a,s) memset(a, s, sizeof a);
#define gcd(a,b) __gcd(a,b)
#define pb(a) push_back(a)
const int mod = 1e6+7;
const int inf = 0x3f3f3f3f;
const int N = 1e5 + 10;
int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};
ll a[N];
ll n, k;
void dfs(ll x, ll y) {
	if(y == 20) return;
	if(x % n == 0 && (x < k || k == 0)) k = x; 
	dfs(x * 10, y + 1);
	dfs(x * 10 + 1, y + 1);
}
void solve() {
	cin >> n;
	dfs(1, 1);
	if(k) cout << k / n;
	else cout << "No Solution";
}
int main()
{
	int t = 1;

//	cin >> t;

	while(t --) {
		solve();
	}

	return 0;
}

上面是火炬