Skittles

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <queue>
#include <climits>
using namespace std;
typedef long long ll;

const ll MOD = 998244353;

ll gcd(ll a, ll b) {
    while (b) {
        a %= b;
        swap(a, b);
    }
    return a;
}

ll modPow(ll base, ll exp, ll mod) {
    ll result = 1;
    base %= mod;
    while (exp > 0) {
        if (exp & 1) {
            result = (result * base) % mod;
        }
        base = (base * base) % mod;
        exp >>= 1;
    }
    return result;
}

ll modInverse(ll a, ll m) {
    // For prime modulus, use Fermat's Little Theorem: a^(-1) = a^(p-2) mod p
    return modPow(a, m - 2, m);
}

ll binomialCoeff(ll n, ll k, vector<ll> &fac, vector<ll> &inv_fac) {
    if (k > n || k < 0) return 0;
    if (k == 0 || k == n) return 1;
    
    return fac[n] * inv_fac[k] % MOD * inv_fac[n - k] % MOD;
}

ll lcm(ll a, ll b) {
    return (a / gcd(a, b)) * b;
}

void task1(){
    ll n, q;
    cin >> n >> q;

    vector<pair<ll,ll>> arr(q);

    for(ll i = 0; i < q; i++){
        ll a, b;
        cin >> a >> b;
        arr[i] = {a, b};
    }

    for(ll i = 0; i < q; i++){
        cout << lcm(arr[i].first, n) / arr[i].first << endl;
    }
}

void task2(){
    ll n, a, b;
    cin >> n >> a >> b;

    ll maxN = n + b;
    vector<ll> fact(maxN + 1);
    fact[0] = 1;
    for(ll i = 1; i <= maxN; i++){
        fact[i] = (fact[i-1] * i) % MOD;
    }
    
    vector<ll> inv_fact(maxN + 1);
    inv_fact[maxN] = modInverse(fact[maxN], MOD);
    for(ll i = maxN - 1; i >= 0; i--){
        inv_fact[i] = (inv_fact[i + 1] * (i + 1)) % MOD;
    }

    ll total = 0;
    for(ll i = a; i <= b; i++){
        total = (total + binomialCoeff(n + i - 1, i, fact, inv_fact)) % MOD;
    }

    cout << total << endl;
}

void task3(){
    ll n, y;
    cin >> n >> y;

    vector<ll> arr(n);
    for(ll i = 0; i < n; i++){
        cin >> arr[i];
    } 
    
    for(ll i = 0; i < n; i++){
        if(gcd(y, arr[i]) != 1){
            cout << "Yes" << endl;
            return;
        }
    }
    cout << "No" << endl;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    task2();
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: ACCEPTED

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: ACCEPTED

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: ACCEPTED

Test 41

Verdict: ACCEPTED

Test 42

Verdict: ACCEPTED

Test 43

Verdict: ACCEPTED

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: ACCEPTED

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: ACCEPTED

Test 50

Verdict: ACCEPTED

Test 51

Verdict: ACCEPTED

Test 52

Verdict: ACCEPTED

Test 53

Verdict: ACCEPTED

Test 54

Verdict: ACCEPTED

Test 55

Verdict: ACCEPTED

Test 56

Verdict: ACCEPTED

Test 57

Verdict: ACCEPTED

Test 58

Verdict: ACCEPTED

Test 59

Verdict: ACCEPTED

Test 60

Verdict: ACCEPTED

Test 61

Verdict: ACCEPTED

Test 62

Verdict: ACCEPTED

Test 63

Verdict: ACCEPTED