Submission #3784295


Source Code Expand

#include<iostream>
#include<cstring>
#include<cstdio>
#include<map>
#include<set>
#include<vector>
#include<algorithm>
#include<cmath>
#include<fstream>
#include<iomanip>
#include<unordered_set>
using namespace std;
typedef long long ll;
typedef unsigned long long ull; 
const ll mod = 998244353;
const ll N = 3 * 100000 + 5;
ll Mode(ll a, ll b){
	ll sum = 1;
	while (b) {
		if (b & 1) {
			sum = (sum * a) % mod;
			b--;
		}
		b /= 2;
		a = a * a % mod;
	}
	return sum;
}
//快速幂取模 

ll inv(ll a){
	return Mode(a, mod - 2);
}
//逆元 

ll jc[N];
void init() //预处理算阶乘
{
    jc[0] = 1;
    for(int i = 1; i < N; ++i)
    jc[i] = jc[i-1] * i % mod;
}
ll C(ll n, ll m){
    if(n<0||m>n)
        return 0;
    return ((jc[n] % mod) * ((inv(jc[m]) * inv(jc[n - m])) % mod)) % mod;
}//组合数 
int main(){
//	ios::sync_with_stdio(false);
//	ifstream cin("data.txt");
//	freopen("data.txt", "r", stdin);
	init();
	ll n, a, b, k;
	ll ans = 0;
	cin >> n >> a >> b >> k;
	if(k == 0){
		cout << 1 << endl;
		return 0;
	}
	for(ll i = 1; i <= n; i++){
		
		if(!((k - a * i) % b)){
			ll t1 = i;
			ll t2 = ((k - a * i) / b); 
			ll cnt = C(n, t1);
			cnt %= mod;
			cnt *= C(n, t2);
			cnt %= mod; 
			ans += cnt;
			ans %= mod;
		}
	}
	cout << ans << endl;
	return 0;
}

Submission Info

Submission Time
Task B - RGB Coloring
User sheeeeeeep
Language C++14 (GCC 5.4.1)
Score 0
Code Size 1354 Byte
Status RE
Exec Time 173 ms
Memory 2560 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 0 / 700
Status
AC × 3
AC × 18
RE × 9
Set Name Test Cases
Sample sample01.txt, sample02.txt, sample03.txt
All sample01.txt, sample02.txt, sample03.txt, in01.txt, in02.txt, in03.txt, in04.txt, in05.txt, in06.txt, in07.txt, in08.txt, in09.txt, in10.txt, in11.txt, in12.txt, in13.txt, in14.txt, in15.txt, in16.txt, in17.txt, in18.txt, in19.txt, in20.txt, in21.txt, sample01.txt, sample02.txt, sample03.txt
Case Name Status Exec Time Memory
in01.txt RE 103 ms 2560 KB
in02.txt AC 102 ms 2560 KB
in03.txt RE 102 ms 2560 KB
in04.txt AC 7 ms 2560 KB
in05.txt AC 7 ms 2560 KB
in06.txt RE 102 ms 2560 KB
in07.txt RE 103 ms 2560 KB
in08.txt AC 5 ms 2560 KB
in09.txt AC 7 ms 2560 KB
in10.txt AC 6 ms 2560 KB
in11.txt RE 102 ms 2560 KB
in12.txt AC 5 ms 2560 KB
in13.txt RE 137 ms 2560 KB
in14.txt AC 11 ms 2560 KB
in15.txt RE 106 ms 2560 KB
in16.txt RE 106 ms 2560 KB
in17.txt RE 141 ms 2560 KB
in18.txt AC 129 ms 2560 KB
in19.txt AC 173 ms 2560 KB
in20.txt AC 166 ms 2560 KB
in21.txt AC 4 ms 2560 KB
sample01.txt AC 4 ms 2560 KB
sample02.txt AC 4 ms 2560 KB
sample03.txt AC 5 ms 2560 KB