Submission #855896

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Source Code Expand

#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <utility>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
#include <istream>
#include <ostream>

#include <cstdlib>
#include <cmath>
#include <cstdio>

using namespace std;

#define fi first
#define se second
#define mkp make_pair
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define rep(i,n) for(ll i=0; i < (n); ++i)
#define rrep(i,n) for(ll i=((n)-1); i >= 0; --i)

#define OPLT(T) bool operator<(const T & lop_, const T & rop_)
#define OPEQ(T) bool operator==(const T & lop_, const T & rop_)

typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

istream& operator>>(istream& istr, __float128& obj) { double d; istr >> d; obj = d; return istr; };
ostream& operator<<(ostream& ostr, __float128& obj) { ostr << static_cast<double>(obj); return ostr; };

template<class T>
T sqr(const T & a) {
	return a * a;
}

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

int main() {
	ll n, s;
	ll b = -1;
	cin >> n >> s;
	for(ll i = 2; sqr(max(i-10,0ll)) <= n; i++) {
		if(f(i, n) == s) {
			b = i;
			break;
		}
	}
	if(n-s > 0) for(ll i = 1; sqr(max(i-10,0ll)) <= n; i++) {
		if((n-s) % i == 0) {
			ll bb = (n-s) / i + 1;
			if(n/bb == i) {
				if(b < 0) b = bb;
				b = min(b, bb);
			}
		}
	}
	cout << b << endl;
	return 0;
}

Submission Info

Judge Result