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Submission #1106729

# Submission time Handle Problem Language Result Execution time Memory
1106729 2024-10-31T01:52:32 Z 12345678 Boat (APIO16_boat) C++17
9 / 100
 2000 ms 12416 KB 
#include <bits/stdc++.h>

using namespace std;

#define ll long long

const int nx=505, mod=1e9+7;
ll n, a[nx], b[nx], dp[nx][2*nx], qs[nx][2*nx], sz[2*nx], t, pv, ncr[nx][nx], choose[2*nx][nx], l[nx], r[nx];
map<ll, ll> mp;

ll invmod(ll a, ll x)
{
    if (x==0) return 1;
    auto tmp=invmod(a, x/2);
    tmp=(tmp*tmp)%mod;
    if (x%2) return (tmp*a)%mod;
    else return tmp;
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n;
    mp[0]=0;
    for (int i=1; i<=n; i++) cin>>a[i]>>b[i], mp[--a[i]]=0, mp[b[i]]=0;
    for (auto &[x, y]:mp) y=t, sz[t]=x-pv, pv=x, t++;
    for (int i=1; i<=n; i++) l[i]=mp[a[i]], r[i]=mp[b[i]];
    ncr[0][0]=1;
    for (int i=1; i<=n; i++)
    {
        for (int j=0; j<=i; j++)
        {
            ncr[i][j]=ncr[i-1][j];
            if (j>0) ncr[i][j]=(ncr[i][j]+ncr[i-1][j-1])%mod;
        }
    }
    for (int i=1; i<t; i++)
    {
        //cout<<"sz "<<i<<' '<<sz[i]<<'\n';
        ll tmp=1;
        choose[i][0]=tmp;
        for (int j=1; j<=min(sz[i], n); j++) tmp=(((tmp*(sz[i]-j+1))%mod)*invmod(j, mod-2))%mod, choose[i][j]=tmp;
    }
    for (int i=1; i<=n; i++)
    {
        //cout<<"l "<<i<<' '<<l[i]<<' '<<r[i]<<'\n';
        for (int j=1; j<t; j++)
        {
            if (l[i]<j&&j<=r[i])
            {
                dp[i][j]=((qs[i-1][j-1]+1)*sz[j])%mod;
                ll cnt=1;
                for (int k=i-1; k>=1; k--)
                {
                    if (l[k]<j&&j<=r[k]) cnt++;
                    //if (i==n) cout<<"debug "<<k<<' '<<cnt<<'\n';
                    if (cnt>=2)
                    {
                        ll sm=0;
                        for (int tmp=0; tmp<=cnt-2; tmp++) sm=(sm+choose[j][tmp+2]*ncr[cnt-2][tmp])%mod;
                        //if (i==n) cout<<"sm "<<sm<<'\n', cout<<"choose "<<choose[1][0]<<' '<<ncr[1][0]<<'\n';
                        dp[i][j]=(dp[i][j]+sm*(qs[k-1][j-1]+1))%mod;
                    }
                }
            }
            //cout<<"dp "<<i<<' '<<j<<' '<<dp[i][j]<<'\n';
            qs[i][j]=((dp[i][j]+qs[i-1][j]+qs[i][j-1]-qs[i-1][j-1])%mod+mod)%mod;
        }
    }
    cout<<qs[n][t-1];
}

/*
2
1 3
1 3
*/

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 63 ms 12360 KB Output is correct
2 Correct 59 ms 12360 KB Output is correct
3 Correct 60 ms 12304 KB Output is correct
4 Correct 60 ms 12360 KB Output is correct
5 Correct 56 ms 12360 KB Output is correct
6 Correct 56 ms 12360 KB Output is correct
7 Correct 56 ms 12360 KB Output is correct
8 Correct 59 ms 12364 KB Output is correct
9 Correct 56 ms 12416 KB Output is correct
10 Correct 56 ms 12392 KB Output is correct
11 Correct 57 ms 12412 KB Output is correct
12 Correct 57 ms 12360 KB Output is correct
13 Correct 58 ms 12360 KB Output is correct
14 Correct 57 ms 12360 KB Output is correct
15 Correct 60 ms 12360 KB Output is correct
16 Correct 17 ms 11088 KB Output is correct
17 Correct 17 ms 11088 KB Output is correct
18 Correct 16 ms 11088 KB Output is correct
19 Correct 17 ms 11088 KB Output is correct
20 Correct 16 ms 11088 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 63 ms 12360 KB Output is correct
2 Correct 59 ms 12360 KB Output is correct
3 Correct 60 ms 12304 KB Output is correct
4 Correct 60 ms 12360 KB Output is correct
5 Correct 56 ms 12360 KB Output is correct
6 Correct 56 ms 12360 KB Output is correct
7 Correct 56 ms 12360 KB Output is correct
8 Correct 59 ms 12364 KB Output is correct
9 Correct 56 ms 12416 KB Output is correct
10 Correct 56 ms 12392 KB Output is correct
11 Correct 57 ms 12412 KB Output is correct
12 Correct 57 ms 12360 KB Output is correct
13 Correct 58 ms 12360 KB Output is correct
14 Correct 57 ms 12360 KB Output is correct
15 Correct 60 ms 12360 KB Output is correct
16 Correct 17 ms 11088 KB Output is correct
17 Correct 17 ms 11088 KB Output is correct
18 Correct 16 ms 11088 KB Output is correct
19 Correct 17 ms 11088 KB Output is correct
20 Correct 16 ms 11088 KB Output is correct
21 Execution timed out 2059 ms 11088 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 19 ms 5712 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 63 ms 12360 KB Output is correct
2 Correct 59 ms 12360 KB Output is correct
3 Correct 60 ms 12304 KB Output is correct
4 Correct 60 ms 12360 KB Output is correct
5 Correct 56 ms 12360 KB Output is correct
6 Correct 56 ms 12360 KB Output is correct
7 Correct 56 ms 12360 KB Output is correct
8 Correct 59 ms 12364 KB Output is correct
9 Correct 56 ms 12416 KB Output is correct
10 Correct 56 ms 12392 KB Output is correct
11 Correct 57 ms 12412 KB Output is correct
12 Correct 57 ms 12360 KB Output is correct
13 Correct 58 ms 12360 KB Output is correct
14 Correct 57 ms 12360 KB Output is correct
15 Correct 60 ms 12360 KB Output is correct
16 Correct 17 ms 11088 KB Output is correct
17 Correct 17 ms 11088 KB Output is correct
18 Correct 16 ms 11088 KB Output is correct
19 Correct 17 ms 11088 KB Output is correct
20 Correct 16 ms 11088 KB Output is correct
21 Execution timed out 2059 ms 11088 KB Time limit exceeded
22 Halted 0 ms 0 KB -