Submission #857144

---

Source Code Expand

#include<iostream>
#include<iomanip>
#include<algorithm>
#include<array>
#include<bitset>
#include<cassert>
#include<cctype>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<functional>
#include<limits>
#include<list>
#include<map>
#include<numeric>
#include<set>
#include<stack>
#include<string>
#include<sstream>
#include<queue>
#include<vector>
using namespace std;

using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;

#define dump(o) { cerr << #o << " " << o << endl; }
#define dumpc(o) { cerr << #o; for (auto &e : (o)) cerr << " " << e; cerr << endl; }
#define MOD 1000000007
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL

ll f(ll b, ll n) {
	if (b > n)return n;
	return f(b, n / b) + n%b;
}

signed main() {
	ll n, s; cin >> n >> s;
	//for (int h = 1000; h < 2000; h++) {
	//	for (int i = 2; i < n; i++) {
	//		if (f(i, n) == h) {
	//			dump(i);
	//			dump(f(i, n));
	//			break;
	//		}
	//	}
	//}

	//for (int h = 1; h < 1000; h++) {
	//	ll M = 0;
	//	for (int i = 2; i < h; i++) {
	//		if (M < f(i, h)) {
	//			M = f(i, h);
	//		}
	//	}
	//	cout << h << " " << M << endl;
	//}

	if ((n + 1) / 2 < s) {
		cout << -1 << endl;
	}
	else {
		for (ll i = 2; i < n; i++) {
			if (f(i, n) == s) {
				//dump(i);
				//dump(f(i, n));
				cout << i << endl;
				break;
			}
		}
	}
	return 0;
}

Submission Info

Judge Result