Lazy Security Guard
Your security guard friend recently got a new job at a new security company. The company requires him to patrol an area of the city encompassing exactly N city blocks, but they let him choose which blocks. That is, your friend must walk the perimeter of a region whose area is exactly N blocks. Your friend is quite lazy and would like your help to find the shortest possible route that meets the requirements. The city is laid out in a square grid pattern, and is large enough that for the sake of the problem it can be considered infinite.
Input
Input will consist of a single integer N (1 ≤ N ≤ 106), the number of city blocks that must be enclosed by the route.
Output
Print the minimum perimeter that can be achieved.
Example
Input
4
Output
8
Input
11
Output
14
Input
22
Output
20
Note
Here are some possible shapes for the examples:
题意：给出正方形的个数，拼到一起能够拼出最少的边；
思路：找规律，打表。
#include<stdio.h>
#include<iostream>
#include<algorithm>
#include<string.h>
#include<math.h>
using namespace std;
long long a[1100000];
int main()
{
int n;
a[0]=0;
a[1]=4;
a[2]=6;
long long t=8;
long long q=2;
int i=3;
while(1)
{
for(int j=0; j<q; j++)
{
a[i++]=t;
}
if(i>1000010)
break;
t+=2;
for(int j=0; j<q; j++)
{
a[i++]=t;
}
q++;
t+=2;
if(i>1000010)
break;
}
// for(int i=1;i<=25;i++)
// cout<<a[i]<<endl;
while(~scanf("%d",&n))
{
cout<<a[n]<<endl;
}
}