Aristocracy

use std::io;
use std::collections::HashMap;

const fn factorials() -> [i128; 10000] {
    let mut out = [1i128; 10000];
    let mut i: usize = 1;
    while i < 10000 {
        out[i] = out[i-1] * i as i128;
        out[i] = out[i] % M;
        i += 1;
    }
    out
}

const M: i128 = 1_000_000_007;

fn main() {
    //dbg!(factorials());
    let mut iter = io::stdin().lines();
    let n = iter.next().unwrap().unwrap().trim().parse::<usize>().unwrap();
    let mut titles = HashMap::<String, i128>::new();
    for _ in 0..n {
        let input = {
            let input = iter.next().unwrap().unwrap();
            input.split_whitespace().next().unwrap().to_string()
        };
        if let Some(val) = titles.get_mut(&input) {
            *val += 1;
        } else {
            titles.insert(input, 1);
        }
    }
    let mut inv = 1;
    let mut q: i128 = 1;
    for a in titles {
        q *= factorials()[a.1 as usize];
        q %= M;
    }
    let mut k;
    while q != 1 {
        k = M/q + 1;
        q = (q*k) % M;
        inv *= k;
        inv %= M; 
    }
    println!("{}", (inv*factorials()[n as usize]) % M);
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: RUNTIME ERROR

thread 'main' panicked at input/code.rs:36:14:
index out of bounds: the len is 10000 but the index is 100000
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Test 7

Verdict: RUNTIME ERROR

thread 'main' panicked at input/code.rs:46:25:
index out of bounds: the len is 10000 but the index is 100000
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Test 8

Verdict: RUNTIME ERROR

thread 'main' panicked at input/code.rs:36:14:
index out of bounds: the len is 10000 but the index is 50024
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Test 9

Verdict: RUNTIME ERROR

thread 'main' panicked at input/code.rs:46:25:
index out of bounds: the len is 10000 but the index is 100000
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Test 10

Verdict: TIME LIMIT EXCEEDED

Test 11

Verdict: RUNTIME ERROR

thread 'main' panicked at input/code.rs:36:14:
index out of bounds: the len is 10000 but the index is 100000
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Test 12

Verdict: RUNTIME ERROR

thread 'main' panicked at input/code.rs:46:25:
index out of bounds: the len is 10000 but the index is 100000
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Test 13

Verdict: RUNTIME ERROR

thread 'main' panicked at input/code.rs:36:14:
index out of bounds: the len is 10000 but the index is 50265
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Test 14

Verdict: RUNTIME ERROR

thread 'main' panicked at input/code.rs:46:25:
index out of bounds: the len is 10000 but the index is 100000
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Test 15

Verdict: TIME LIMIT EXCEEDED

Test 16

Verdict: TIME LIMIT EXCEEDED

Test 17

Verdict: ACCEPTED