Submission #1027272

#	Time	Username	Problem	Language	Result	Execution time	Memory
1027272		khanhtb	Binaria (CCO23_day1problem1)	C++14	0 / 25	12 ms	19052 KiB

Main

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define ld long double
#define pb push_back
#define pf push_front
#define vi vector<ll>
#define vii vector<vi>
#define pll pair<ll, ll>
#define vpll vector<pll>
#define all(a) a.begin(), a.end()
#define fi first
#define se second
using namespace std;
const ll mod = 1e6 + 3;
const ll inf = 2e18;
const ll blocksz = 320;
const ll N = 1e6 + 5;
ll n,fac[N],invfac[N];
ll bipow(ll a, ll b){
    ll ans = 1;
    while(b){
        if(b&1) ans = ans*a%mod;
        a = a*a%mod;
        b>>=1;
    }
    return ans;
}
void precalc(){
    fac[0] = 1;
    for(ll i = 1; i < N; i++) fac[i] = fac[i-1]*i%mod;
    invfac[N-1] = bipow(fac[N-1],mod-2);
    for(ll i = N-2; i >= 0; i--) invfac[i] = invfac[i+1]*(i+1)%mod;
}
ll C(ll k, ll n){
    if(k > n) return 0;
    return ((fac[n]*invfac[k])%mod)*invfac[n-k]%mod;
}
ll k,a[N];
ll d[N];
bool ok = 1;
void update(ll i){
    for(ll j = i-k; j >= 1; j--){
        if(a[j] != -1){
            if(a[j] != (a[j+k]^1)) ok = 0;
            break;
        }
        a[j] = a[j+k]^1;
    }
    for(ll j = i+k; j <= n; j += k){
        if(a[j] != -1){
            if(a[j] != (a[j-k]^1)) ok = 0;
            break;
        }
        a[j] = (a[j-k]^1);
    }
}
void solve(){
    cin >> n >> k;
    fill(a,a+n+1,-1);
    for(ll i = 1; i <= n-k+1; i++) cin >> d[i];
    if(k == 1){
        if(*max_element(d+1,d+n-k+1+1) != *min_element(d+1,d+n-k+1+1)) cout << 0;
        else cout << 1;
        return;
    }
    for(ll i = k+1; i <= n; i++){
        if(d[i-k+1] != d[i-k]){
            if(d[i-k+1] > d[i-k]) a[i] = 1, a[i-k] = 0;
            else a[i] = 0, a[i-k] = 1;
            update(i), update(i-k);
        }   
    }
    precalc();
    ll cnt = 0;
    ll n1 = d[1];
    for(ll i = 1; i <= k; i++){
        if(a[i] == -1) cnt++;
        if(a[i] == 1) n1--;
    }
    cout << ok*C(n1,cnt);
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen("test.inp", "r")){
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    ll T = 1;
    // cin >> T;
    for (ll i = 1; i <= T; i++){
        solve();
        cout << '\n';
    }
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:88:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:89:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 3
• Subtask 2: 0 / 3
• Subtask 3: 0 / 4
• Subtask 4: 0 / 4
• Subtask 5: 0 / 4
• Subtask 6: 0 / 7