Submission #1232823

---

Source Code Expand

use std::io;
use std::io::{Read, BufReader};
use std::cmp;

fn next_token<R: Read>(reader: &mut R) -> Vec<u8> {
    let mut buf: [u8; 1] = [0];
    let mut read_chars = false;
    let mut ret: Vec<u8> = vec![];

    loop {
        if reader.read(&mut buf).unwrap() == 0 {
            break;
        } else {
            if buf[0] == '\r' as u8 || buf[0] == '\n' as u8 || buf[0] == ' ' as u8 {
                if read_chars {
                    break;
                }
            } else {
                read_chars = true;
                ret.push(buf[0]);
            }
        }
    };
    ret
}
fn next_i64<R: Read>(reader: &mut R) -> i64 {
    let token = next_token(reader);
    let mut ret: i64 = 0;
    let mut sgn = false;

    for c in token {
        if '0' as u8 <= c && c <= '9' as u8 {
            ret = ret * 10 + (c - ('0' as u8)) as i64;
        } else if '-' as u8 == c {
            sgn = true;
        }
    };
    ret * if sgn { -1 } else { 1 }
}
fn next_i32<R: Read>(reader: &mut R) -> i32 {
    next_i64(reader) as i32
}

fn main() {
    let buf = &mut BufReader::new(io::stdin());

    let x = next_i32(buf);
    let mut i = 1;
    let mut s = 0;
    loop {
        s += i;
        if s >= x {
            println!("{}", i);
            break;
        }
        i += 1;
    }
}

Submission Info

Compile Error

warning: unused import: `std::cmp`, #[warn(unused_imports)] on by default
 --> ./Main.rs:3:5
  |
3 | use std::cmp;
  |     ^^^^^^^^

Judge Result