CF743C 题解

题目链接

(Solution:)

为什么这题有蓝啊(QwQ)。。。

(frac{1}{n}+frac{1}{n+1}+frac{1}{n(n+1)}=frac{2}{n})

(Code:)

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll n;
inline ll read()
{
	ll sum=0,f=1;
	char ch=0;
	while(!isdigit(ch))
	{
		if(ch=='-') f=-1;
		ch=getchar();
	}
	while(isdigit(ch))
	{
		sum=(sum<<1)+(sum<<3)+(ch^48);
		ch=getchar(); 
	}
	return sum*f;
}
int main(void)
{
	n=read();
	if(n==1)
	{
		printf("-1
");
		return 0;
	}
	printf("%lld %lld %lld
",n,n+1,n*(n+1));
	return 0;
}