Problem:
Score : 200 points

Problem Statement

A string is called a KEYENCE string when it can be changed to keyence by removing its contiguous substring (possibly empty) only once.

Given a string S consisting of lowercase English letters, determine if S is a KEYENCE string.

Constraints

The length of S is between 7 and 100 (inclusive).

S consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

If S is a KEYENCE string, print YES; otherwise, print NO.

Sample Input 1

keyofscience

Sample Output 1

YES

keyence is an abbreviation of key of science.

Sample Input 2

mpyszsbznf

Sample Output 2

NO

Sample Input 3

ashlfyha

Sample Output 3

NO

Sample Input 4

keyence

Sample Output 4

YES

Solution in Rust (1.15.1) (judge verdict: Wrong Answer)

// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};

    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };

    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };

    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };

    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };

    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}

fn main() {
    input! {
        s: chars
    }
    let keyence = "keyence".chars().collect::<Vec<char>>();
    let mut c: usize = 0;
    let mut max = 0;
    let mut forward_list = Vec::new();
    for ch in s.iter() {
        if max == keyence.len() {
            ();
        } else if ch == &keyence[c] {
            c += 1;
        } else {
            c = 0;
        }
        max = if max > c { max } else { c };
        forward_list.push(max);
    }
    let keyence_rev = "keyence".chars().rev().collect::<Vec<char>>();
    let mut c: usize = 0;
    let mut max = 0;
    let mut backward_list = std::collections::VecDeque::new();
    for ch in s.iter().rev() {
        if max == keyence_rev.len() {
            ();
        } else if ch == &keyence_rev[c] {
            c += 1;
        } else {
            c = 0;
        }
        max = if max > c { max } else { c };
        backward_list.push_front(max);
    }
    if forward_list[0] == 0 && backward_list[s.len() - 1] == 0 {
        println!("NO");
        std::process::exit(0);
    }
    for i in 0..(s.len() - 1) {
        if forward_list[i] + backward_list[i + 1] >= keyence.len() {
            println!("YES");
            std::process::exit(0);
        }
    }
    println!("NO");
}