Submission #6502641

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Source Code Expand

/***
 * 1. b * b <= n
 * 2. n - s = (b - 1) * p
 */

#pragma GCC optimize(2)

#include <cstdio>
#include <iostream>

using namespace std;

typedef long long LL;

LL n, s;

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

LL solve()
{
	if(n == s) return n + 1;
	for(LL b = 2; b * b <= n; ++b) if(f(b, n) == s) return b;
	if(n < s) return -1;
	LL res = (1LL << 61);
	for(LL i = 1; i * i < n; ++i)
	{
		if((n - s) % i) continue;
		LL b = (n - s) / i + 1LL;
		if(b <= n && f(b, n) == s) res = min(res, b);
	}
	return res != (1LL << 61) ? res : -1LL;
}

int main(void)
{
	scanf("%lld%lld", &n, &s);
	printf("%lld\n", solve());
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:40:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld%lld", &n, &s);
                           ^

Judge Result