C. Fibonacci Words-April Fools Day Contest 2021

Problem - 1505C - Codeforces

C. Fibonacci Words

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

Input

The input consists of a single string of uppercase letters A-Z. The length of the string is between 1 and 10 characters, inclusive.

Output

Output "YES" or "NO".

Examples

input

Copy

HELP

output

Copy

YES

input

Copy

AID

output

Copy

NO

input

Copy

MARY

output

Copy

NO

input

Copy

ANNA

output

Copy

YES

input

Copy

MUG

output

Copy

YES

input

Copy

CUP

output

Copy

NO

input

Copy

SUM

output

Copy

YES

input

Copy

PRODUCT

output

Copy

NO

==============================================================================

愚人节水题，值得注意的是，一旦两字母超过了26这个限度，那么ascll会无法表示这个字母，故我们联想到取模，判断取模之和是否相等即可

#include<iostream>
using namespace std;
 
 
 
int main()
{
 
 
    string s;
 
    cin>>s;
 
 
    int flag=0;
 
    int pre1=0,pre2=0;
 
    pre1=s[0]-'A';
 
    pre2=s[1]-'A';
 
    for(int i=2;i<s.length();i++)
    {
        int now=s[i]-'A';
 
        if((pre1+pre2)%26!=now)
        {
            flag=1;
 
            break;
 
        }
 
        pre1=pre2;
 
        pre2=now;
 
 
    }
 
 
  if(flag)
  {
      cout<<"no";
 
  }
  else
    {cout<<"yes"};
 
    return 0;
 
}