Submission #73917443

---

Source Code Expand

use proconio::input;

fn main() {
    input! {
        k: usize,
        m: u64,
    }

    let mod_val = m * 10007;
    let mod_9 = 9 * mod_val;

    let mut n = 0u64;

    for _ in 0..k {
        input! {
            c: u64,
            l: u64,
        }

        let pow10_9m = mod_pow(10, l, mod_9);
        let sum = (pow10_9m - 1) / 9;
        let sum = sum % mod_val;
        let pow10 = mod_pow(10, l, mod_val);
        n = (n * pow10 + c * sum) % mod_val;
    }

    println!("{}", n / m);
}

fn mod_pow(mut base: u64, mut exp: u64, m: u64) -> u64 {
    let mut result = 1u64;
    base %= m;
    
    while exp > 0 {
        if exp % 2 == 1 {
            result = (result * base) % m;
        }
        base = (base * base) % m;
        exp /= 2;
    }
    
    result
}

Submission Info

Judge Result