Submission #1179830

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Source Code Expand

#include<iostream>
#include<cstdlib>
#include<cstdio>
using namespace std;


long long n;

long long check(int x)
{
	return 1ll*(x+1)*x/2;
}

int main()
{
	cin>>n;
	int l=1,r=n;
	int Ans;
	while(l<=r)
	{
		int mid=l+r>>1;
		if(check(mid)>=n)
		{
			r=mid-1;
			Ans=mid;
		}
		else l=mid+1;
	}
	long long S=check(Ans)-n;
	for(;S&1;S+=++Ans);
	cout<<Ans<<endl;
}

Submission Info

Judge Result