Submission #855456

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Source Code Expand

import java.util.Scanner;

public class Main {

	static Scanner sc = new Scanner(System.in);

	public static void main(String[] args) {
		long N = sc.nextLong();
		long S = sc.nextLong();
		System.out.println(solve(N, S));
	}

	static long solve(long N, long S) {
		for (long b = 2; b * b <= N; ++b) {
			long sum = 0;
			long v = N;
			while (v > 0) {
				sum += v % b;
				v /= b;
			}
			if (sum == S) {
				return b;
			}
		}
		long ans = Long.MAX_VALUE;
		for (long i = 1; i * i <= N - S; ++i) {
			if ((N - S) % i != 0) continue;
			long x = i;
			long b = (N - S) / i + 1;
			long y = N - x * b;
			if (0 <= y && y < b) {
				ans = Math.min(ans, b);
			}
		}
		return ans == Long.MAX_VALUE ? -1 : ans;
	}

}

Submission Info

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