Submission #1560222

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Source Code Expand

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

macro_rules! read {
    ( $( $t:ty ),* ) => {
        {
            let mut buf = String::new();
            io::stdin().read_line(&mut buf);
            let mut sp = buf.trim().split(" ");
            ($(
                {
                    sp.next().unwrap().parse::<$t>().unwrap()
                },
            )*)
        }
    }
}
macro_rules! read_vec {
    ($t:ty) => {
        {
            let mut buf = String::new();
            io::stdin().read_line(&mut buf);
            let mut sp = buf.trim().split(" ");
            let mut ret = vec![];
            for s in sp {
                ret.push(s.parse::<$t>().unwrap());
            }
            ret
        }
    }
}

const MOD: i64 = 998244353;

fn line(a: (i64, i64), b: (i64, i64), c: (i64, i64)) -> bool {
    let b = (b.0 - a.0, b.1 - a.1);
    let c = (c.0 - a.0, c.1 - a.1);

    b.1 * c.0 == b.0 * c.1
}

fn ctri(ni: i64) -> i64 {
    let mut ret = 1i64;
    for _ in 0..ni {
        ret = ret * 2 % MOD;
    }

    ret = (ret + MOD - 1) % MOD;
    ret = (ret + MOD - ni) % MOD;
    ret = (ret + MOD - ni * (ni - 1) / 2) % MOD;

    ret
}

fn main() {
    let (n,) = read!(usize);
    let mut pts = vec![];
    for _ in 0..n {
        pts.push(read!(i64, i64));
    }
    
    let mut lin = vec![0i64; n + 1];

    for i in 0..n {
        for j in (i + 1)..n {
            let mut cnt = 0;
            for k in 0..n {
                if line(pts[i], pts[j], pts[k]) {
                    cnt += 1
                }
            }

            lin[cnt] += 1
        }
    }

    let mut ret = 1i64;
    for _ in 0..n {
        ret = ret * 2 % MOD;
    }

    let ni = n as i64;
    ret = ctri(ni);

    for i in 3..(n + 1) {
        let act = lin[i] / ((i * (i - 1) / 2) as i64);
        ret = (ret + MOD - ctri(i as i64) * act % MOD) % MOD;
    }
    println!("{}", ret);
}

Submission Info

Compile Error

warning: unused imports: `BufReader`, `Read`, #[warn(unused_imports)] on by default
 --> ./Main.rs:2:15
  |
2 | use std::io::{Read, BufReader};
  |               ^^^^  ^^^^^^^^^

warning: unused result which must be used, #[warn(unused_must_use)] on by default
  --> ./Main.rs:8:13
   |
8  |             io::stdin().read_line(&mut buf);
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
56 |     let (n,) = read!(usize);
   |                ------------ in this macro invocation

warning: unused result which must be used, #[warn(unused_must_use)] on by default
  --> ./Main.rs:8:13
   |
8  |             io::stdin().read_line(&mut buf);
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
59 |         pts.push(read!(i64, i64));
   |                  --------------- in this macro invocation

Judge Result