Problem:
Score : 200 points

Problem Statement

You are given an integer sequence A of length N.
Find the maximum absolute difference of two elements (with different indices) in A.

Constraints

2 \leq N \leq 100

1 \leq A_i \leq 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 ... A_N

Output

Print the maximum absolute difference of two elements (with different indices) in A.

Sample Input 1

4
1 4 6 3

Sample Output 1

5

The maximum absolute difference of two elements is A_3-A_1=6-1=5.

Sample Input 2

2
1000000000 1

Sample Output 2

999999999

Sample Input 3

5
1 1 1 1 1

Sample Output 3

0

Solution in Rust (1.15.1) (judge verdict: Accepted)

//https://qiita.com/tanakh
#[allow(unused_macros)]
macro_rules! input {
	(source = $s:expr, $($r:tt)*) => {
		let mut iter = $s.split_whitespace();
		let mut next = || { iter.next().unwrap() }; 
		input_inner!{next, $($r)*}
	};
	($($r:tt)*) => {

		let stdin = std::io::stdin();
		let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock())); 
		let mut next = move || -> String{
			bytes
				.by_ref()
				.map(|r|r.unwrap() as char) 
				.skip_while(|c|c.is_whitespace()) 
				.take_while(|c|!c.is_whitespace()) 
				.collect()
			};
	input_inner!{next, $($r)*} 
	};
}

#[allow(unused_macros)]
macro_rules! input_inner { 
	($next:expr) => {}; 
	($next:expr, ) => {};

	($next:expr, $var:ident : $t:tt $($r:tt)*) => { 
		let $var = read_value!($next, $t); 
		input_inner!{$next $($r)*}
	}; 
}
#[allow(unused_macros)]
macro_rules! read_value { 
	($next:expr, ( $($t:tt),* )) => {
		( $(read_value!($next, $t)),* ) 
	};
	
	($next:expr, [ $t:tt ; $len:expr ]) => {
		(0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
	};

	($next:expr, chars) => {
		read_value!($next, String).chars().collect::<Vec<char>>()
	};
	
	($next:expr, bytes) => {
		read_value!($next, String).into_bytes()
	};
	
	($next:expr, usize1) => { 
		read_value!($next, usize) - 1
	};

	($next:expr, $t:ty) => {
		$next().parse::<$t>().expect("Parse error")
	};
}
fn main(){
	input!{
		n : usize,
		a : [(usize); n],
	}
	let mut Max : usize = a[0];
	let mut Min : usize = a[0];
	for i in 1..n {
		if Max < a[i] {
			Max = a[i];
		}
		if Min > a[i] {
			Min = a[i];
		}
		//println!("{} {}",Max,Min);
	}
	println!("{}",Max-Min);
}