Submission #2612535


Source Code Expand

#include <bits/stdc++.h>
using namespace std;

#define NDEBUG
#ifdef DEBUG
#include "cout11.h"
#undef NDEBUG
#endif
#include <cassert>

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> ii;
typedef pair<ll,ll> llll;
typedef pair<double,double> dd;

typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;

#define sz(a)  int((a).size())
#define pb  push_back
#define FOR(var,from,to) for(int var=(from);var<=(to);++var)
#define rep(var,n)  for(int var=0;var<(n);++var)
#define rep1(var,n)  for(int var=1;var<=(n);++var)
#define repC2(vari,varj,n)  for(int vari=0;vari<(n)-1;++vari)for(int varj=vari+1;varj<(n);++varj)
#define ALL(c)  (c).begin(),(c).end()
#define RALL(c)  (c).rbegin(),(c).rend()
#define tr(i,c)  for(auto i=(c).begin(); i!=(c).end(); ++i)
#define found(s,e)  ((s).find(e)!=(s).end())
#define mset(arr,val)  memset(arr,val,sizeof(arr))
#define mid(x,y) ((x)+((y)-(x))/2)
#define IN(x,a,b) ((a)<=(x)&&(x)<=(b))

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

const ll M=998244353LL;

ll ADD(ll x, ll y) { return (x+y) % M; }
ll SUB(ll x, ll y) { return (x-y+M) % M; }
ll MUL(ll x, ll y) { return x*y % M; }
ll POW(ll x, ll e) { ll v=1; for(; e; x=MUL(x,x), e>>=1) if (e&1) v = MUL(v,x); return v; }
ll DIV(ll x, ll y) { assert(y%M!=0); return MUL(x, POW(y, M-2)); }
ll comb(ll n, ll k) { ll v=1; for(ll i=1; i<=k; i++) v = DIV(MUL(v, n-i+1),i); return v; }

// ax+by=gcd(a,b) を満たすx,yを1組求めたい時に
ll extgcd(ll a, ll b, ll &x, ll &y, ll c=1, ll d=0, ll e=0, ll f=1) {
  if (b == 0) {
    x = c; y = e;  // dot([c,d; e,f], [1;0])
    return a;
  }
  ll q = a/b, r = a%b;
  return extgcd(b, r, x, y, d, c-q*d, f, e-q*f);  // dot([c,d; e,f], [0,1; 1,-q])
}

pair<ll,ll> abc(ll a, ll b, ll c){
    // ax + by = c
    ll g = gcd(gcd(a,b),c);
    a /= g; b /= g; c /= g;

    ll x, y;
    extgcd(a,b,x,y);
    x *= c, y *= c;
#ifdef DEBUG
    // printf("%lldx + %lldy = %lld -> (x=%lld, y=%lld)\n", a*g,b*g,c*g, x,y);
#endif
    return make_pair(x, y);
}

int N, A, B;
ll K;
ll fact[300001];

ll pat(ll r, ll g, ll b, ll n){
    if (r<0 || g<0 || b<0) return 0;
    ll n_ = fact[N];
//    ll rgb_ = MUL(MUL(fact[r], fact[g]), fact[b]);
    ll rgb_ = MUL(MUL(fact[r], fact[g]),
                MUL(fact[b], fact[N-r-g-b]));
    return DIV(n_, rgb_);
}

ll solve() {
    // Ax + By = K な x,yを求める

    ll gab = gcd(A,B);
    ll a_ = A / gab, b_ = B / gab;

    pair<ll,ll> xy = abc(A,B,K);
    ll x = xy.first, y = xy.second;
    if (y < 0) {
        ll dy = -y / a_;
        y += a_ * dy;
        x -= b_ * dy;
        if (y < 0) { y += a_; x -= b_; }
    }
    if (x < 0) {
        ll dx = -x / b_;
        x += b_ * dx;
        y -= a_ * dx;
        if (x < 0) { x += b_; y -= a_; }
    }
    if (x < 0 || y < 0) return 0;
    // y>=0, x>= 0

    ll ans = 0;
    for (ll xi=x,yi=y; xi>=0 && yi<=K; ) {
        // printf("(%lld, %lld)\n", xi, yi);
        ans = ADD(ans, MUL(comb(N, xi), comb(N,yi)));
        xi -= b_; yi += a_;
    }
    for (ll xi=x+b_, yi=y-a_; xi<=K && yi>=0; ) {
        // printf("(%lld, %lld)\n", xi, yi);
        ans = ADD(ans, MUL(comb(N, xi), comb(N,yi)));
        xi += b_; yi -= a_;
    }

    return ans;
}

int main() {
    fact[0] = fact[1] = 1LL;
    for (ll i=2; i<=300000; ++i) {
        fact[i] = MUL(fact[i-1], i);
    }

    cin >> N >> A >> B >> K;
    cout << solve() << endl;
    return 0;
}

Submission Info

Submission Time
Task B - RGB Coloring
User naoya_t
Language C++14 (GCC 5.4.1)
Score 0
Code Size 3623 Byte
Status TLE
Exec Time 2104 ms
Memory 2560 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 0 / 700
Status
AC × 3
AC × 18
TLE × 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 AC 693 ms 2560 KB
in02.txt TLE 2104 ms 2560 KB
in03.txt AC 154 ms 2560 KB
in04.txt AC 1310 ms 2560 KB
in05.txt AC 526 ms 2560 KB
in06.txt AC 185 ms 2560 KB
in07.txt AC 1339 ms 2560 KB
in08.txt AC 800 ms 2560 KB
in09.txt AC 592 ms 2560 KB
in10.txt AC 36 ms 2560 KB
in11.txt AC 83 ms 2560 KB
in12.txt AC 14 ms 2560 KB
in13.txt TLE 2103 ms 2560 KB
in14.txt TLE 2103 ms 2560 KB
in15.txt TLE 2104 ms 2560 KB
in16.txt TLE 2104 ms 2560 KB
in17.txt TLE 2103 ms 2560 KB
in18.txt TLE 2104 ms 2560 KB
in19.txt TLE 2104 ms 2560 KB
in20.txt TLE 2104 ms 2560 KB
in21.txt AC 3 ms 2560 KB
sample01.txt AC 3 ms 2560 KB
sample02.txt AC 3 ms 2560 KB
sample03.txt AC 43 ms 2560 KB