Submission #2738166

---

Source Code Expand

#include <cstdio>
#include <iostream>
#include <string>
#include <vector>
#include <sstream>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <typeinfo>
#include <numeric>
#include <functional>
#include <unordered_map>
#include <bitset>


using namespace std;
using ll = long long;
using ull = unsigned long long;

const ll INF = 1e16;
const ll MOD = 1e9 + 7;

#define REP(i, n) for(ll i = 0; i < n; i++)




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

int main() {
    ll n, s;
    cin >> n >> s;
    
    if(s == n){
        cout << n + 1 << endl;
        return 0;
    }
    
    for(ll b = 2; b <= sqrt(n); b++){
        if(f(b, n) == s){
            cout << b << endl;
            return 0;
        }
    }
    
    for(ll p = 1; p <= sqrt(n); p++){
        ll b = (n - s) / p + 1;
        if(b < 2)continue;
        if(f(b, n) == s){
            cout << b << endl;
            return 0;
        }
    }
    
    cout << -1 << endl;
}

Submission Info

Judge Result