Submission #3187625

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Source Code Expand

#![allow(unused_imports)]
use std::io::*;
use std::fmt::*;
use std::str::*;
use std::cmp::*;
use std::collections::*;

pub trait InputValue {
    fn parse(s: &str) -> Self;
}

pub fn read<T: InputValue>() -> T {
    let mut buf = String::new();
    let _ = stdin().read_line(&mut buf);
    T::parse(&buf.trim())
}

pub fn readn<T: InputValue>(n: usize) -> Vec<T> {
    let mut vec = vec![];
    for _ in 0..n {
        vec.push(read());
    }
    vec
}

pub fn readnc<T: InputValue>() -> Vec<T> {
    let mut vec = vec![];
    let line: String = read();
    for token in line.split_whitespace() {
        vec.push(T::parse(token));
    }
    vec
}

macro_rules! parse_single_value {
    ($($t:ty),*) => {
        $(
            impl InputValue for $t {
                fn parse(s: &str) -> $t { s.parse().unwrap() }
            }
        )*
	}
}
parse_single_value!(i32, i64, f32, f64, usize, String);

macro_rules! parse_tuple {
	($($t:ident),*) => {
		impl<$($t),*> InputValue for ($($t),*) where $($t: InputValue),* {
			fn parse(s: &str) -> ($($t),*) {
				let mut tokens = s.split_whitespace();
				let t = ($($t::parse(tokens.next().unwrap())),*);
				t
			}
		}
	}
}
parse_tuple!(A, B);
parse_tuple!(A, B, C);

// ===

type Katana = (i64, i64);

fn main() {
    let (n, h): (usize, i64) = read();
    let mut katana: Vec<Katana> = readn(n);
    katana.sort_by_key(|k| -k.1);

    let mut slash = 0;
    for k in &katana {
        slash = max(slash, k.0);
    }

    let mut best = (h + slash - 1) / slash;
    let mut throw = 0;
    for i in 0..n {
        throw += katana[i].1;
        let mut sl = i as i64 + 1;
        if h > throw {
            sl += (h - throw + slash - 1) / slash;
        }
        best = min(best, sl);
    }
    println!("{}", best);
}

Submission Info

Judge Result