Submission #1016115

#	Time	Username	Problem	Language	Result	Execution time	Memory
1016115		Khanhcsp2	Binaria (CCO23_day1problem1)	C++14	25 / 25	59 ms	21536 KiB

Main

#include<bits/stdc++.h>
#define el '\n'
#define fi first
#define sc second
#define int ll
#define pii pair<int, int>
#define all(v) v.begin(), v.end()
using namespace std;
using ll=long long;
using ull=unsigned long long;
using ld=long double;
const int mod=1e6+3;
const int N=1e6+11;
int n, k, a[N], ned[N], f[N];
int po(int a, int b)
{
    int r=1;
    while(b)
    {
        if(b&1) r=r*a%mod;
        b/=2;
        a=a*a%mod;
    }
    return r%mod;
}
void sol()
{
    cin >> n >> k;
    for(int i=1;i<=n-k+1;i++) cin >> a[i];
    for(int i=1;i<=n;i++) ned[i]=-1;
    for(int i=n-k;i>=1;i--)
    {
        if(abs(a[i]-a[i+1])>=2)
        {
            cout << 0;
            return;
        }
        if(a[i]>a[i+1])
        {
            if(ned[i+k]==1)
            {
                cout << 0;
                return;
            }
            ned[i]=1;
        }
        else if(a[i]<a[i+1])
        {
            if(ned[i+k]==0)
            {
                cout << 0;
                return;
            }
            ned[i]=0;
        }
        else if(a[i]==a[i+1]) ned[i]=ned[i+k];
    }
    int s1=a[1], s2=0;
    for(int i=1;i<=k;i++)
    {
        if(ned[i]==1) s1--;
        else if(ned[i]==-1) s2++;
    }
    f[0]=1;
    for(int i=1;i<=k;i++) f[i]=f[i-1]*i%mod;
    if(s1>s2) cout << 0;
    else cout << f[s2]*po(f[s1], mod-2)%mod*po(f[s2-s1], mod-2)%mod;

}
signed main()
{
//    freopen("divisor.INP", "r", stdin);
//    freopen("divisor.OUT", "w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t=1;
    //cin >> t;
    while(t--)
    {
        sol();
    }
}

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