Submission #761926

#	Time	Username	Problem	Language	Result	Execution time	Memory
761926		bgnbvnbv	Žarulje (COI15_zarulje)	C++14	100 / 100	294 ms	20516 KiB

zarulje

#include<bits/stdc++.h>
#define TASKNAME "codeforce"
#define pb push_back
#define pli pair<int,int>
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL);
using namespace std;
using ll=long long;
const ll maxN=2e5+10;
const ll inf=1e18;
const ll mod=1e9+7;
ll n,k,a[maxN],p[maxN];
vector<int> dq,st;
vector<pli> D;
ll nho[maxN];
ll ans[maxN];
ll luu=1;
ll cnt[2][maxN];
ll f[2*maxN],fr[2*maxN];
ll pw(ll x,ll y)
{
    if(y==0) return 1;
    ll x1=pw(x,y/2);
    x1=x1*x1%mod;
    if(y&1) x1=x1*x%mod;
    return x1;
}
ll C(ll k,ll n)
{
    return f[n]*fr[k]%mod*fr[n-k]%mod;
}
void c(ll t,ll x,ll v)
{
    luu=luu*pw(C(cnt[t][x],cnt[t][x]+cnt[1-t][x]),mod-2)%mod;
    cnt[t][x]+=v;
    luu=luu*C(cnt[t][x],cnt[t][x]+cnt[1-t][x])%mod;
}
void rollback(ll x)
{
    while(D.size()>x)
    {
        if(D.back().fi==0)
        {
            dq.pb(D.back().se);
            c(1,D.back().se,1);
        }
        else
        {
            dq.pop_back();
            c(1,D.back().se,-1);
        }
        D.pop_back();
    }
}
void solve()
{
    cin >> n >> k;
    for(int i=1;i<=n;i++) cin >> a[i];
    //for(int i=1;i<=k;i++) cin >> p[i];
    f[0]=1;
    for(ll i=1;i<=2*n;i++)
    {
        f[i]=f[i-1]*i%mod;
    }
    fr[2*n]=pw(f[2*n],mod-2);
    for(ll i=2*n-1;i>=0;i--)
    {
        fr[i]=fr[i+1]*(i+1)%mod;
    }
    for(int i=n;i>=1;i--)
    {
        while(dq.size()>0&&a[i]<dq.back())
        {
            D.pb({0,dq.back()});
            c(1,dq.back(),-1);
            dq.pop_back();
        }
        dq.pb(a[i]);
        D.pb({1,dq.back()});
        c(1,dq.back(),1);
        nho[i]=D.size();
    }

    for(int i=1;i<=n;i++)
    {
        rollback(nho[i+1]);
        if(i>1)
        {
            while(st.size()>0&&a[i-1]<st.back())
            {
                c(0,st.back(),-1);
                st.pop_back();
            }
            st.pb(a[i-1]);
            c(0,st.back(),1);
        }
        ans[i]=luu;
    }
    for(int i=1;i<=k;i++)
    {
        ll p;
        cin >> p;
        cout << ans[p]<<'\n';
    }
}
int main()
{
    fastio
    //freopen(TASKNAME".INP","r",stdin);
    //freopen(TASKNAME".OUT","w",stdout);
    solve();
}

Compilation message (stderr)

zarulje.cpp: In function 'void rollback(ll)':
zarulje.cpp:41:19: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   41 |     while(D.size()>x)
      |           ~~~~~~~~^~

• Subtask 1: 22 / 22
• Subtask 2: 38 / 38
• Subtask 3: 40 / 40