[2016-04-14] [Codeforces] [630] D [Hexagons!]

• Time: 2016-04-14-23:54:07 Thursday
• Title number: [2016-04-14][codeforces][630][d][hexagons!]
• The main idea of the topic: as the title of the figure, ask the outermost is n, the total number of lattice
• Analysis:
  • Observation can be obtained, a n TableshownSectionNCircleof theLatticeChildnumber,the a n =6xN(N>0), a 0 =1 a n Table shown Section N Circle of the Lattice Child number , the a n = 6 x N ( N > 0 ) , a 0 = 1
  • So eventually aNs=1+6+ A+... ..+6xN=(3+3N)N+1 a n s = 1 + 6 + + ... + 6 x N = ( 3 + 3 n ) N + 1 ;
• Problems encountered: Using the cumulative method will be T

  
 

   
  

  
#include<cstdio>
   
  

  
using namespace std;
   
  

  
typedef long long ll;
   
  

  
int main(){
   
  

  
 int n;
   
  

  
 scanf("%d",&n);
   
  

  
 ll ans = (3 + 3 *(ll)n)*n + 1;
   
  

  
 printf("%I64d\n",ans);
   
  

  
 return 0;
   
  

  
}
  
 

From for notes (Wiz)

[2016-04-14] [Codeforces] [630] D [Hexagons!]