oj.uz

Submission #310013

# Submission time Handle Problem Language Result Execution time Memory
310013 2020-10-05T10:22:34 Z vipghn2003 Boat (APIO16_boat) C++14
27 / 100
 1742 ms 10452 KB 
#include<bits/stdc++.h>
#define int long long
using namespace std;

const int N=505;
const int mod=1e9+7;
int n,l[N],r[N],dp[N][N*2],sum[N][N*2],igt[N],gt[N],ways[N][N*2];

int Power(int x,int n)
{
    if(!n) return 1;
    if(n%2) return Power(x,n-1)*x%mod;
    int tmp=Power(x,n/2);
    return tmp*tmp%mod;
}

void init()
{
    gt[0]=1;
    for(int i=1;i<=N-5;i++) gt[i]=gt[i-1]*i%mod;
    igt[N-5]=Power(gt[N-5],mod-2);
    for(int i=N-5-1;i>=0;i--) igt[i]=igt[i+1]*(i+1)%mod;
}

int C(int k,int n)
{
    if(k<0||k>n) return 0;
    if(n<=500) return gt[n]*igt[n-k]%mod*igt[k]%mod;
    int res=igt[k];
    for(int i=n-k+1;i<=n;i++) res=res*i%mod;
    return res%mod;
}

main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin>>n;
    init();
    vector<int>val;
    for(int i=1;i<=n;i++)
    {
        cin>>l[i]>>r[i];
        r[i]++;
        val.push_back(l[i]);
        val.push_back(r[i]);
    }
    val.push_back(0);
    sort(val.begin(),val.end());
    val.erase(unique(val.begin(),val.end()),val.end());
    for(int i=1;i<=n;i++)
    {
        l[i]=lower_bound(val.begin(),val.end(),l[i])-val.begin();
        r[i]=lower_bound(val.begin(),val.end(),r[i])-val.begin();
    }
    int sz=val.size()-1;
    for(int i=1;i<=sz-1;i++)
    {
        for(int k=1;k<=n;k++)
        {
            int cur=C(k,val[i+1]-val[i]);
            for(int j=k;j<=n;j++) ways[i][j]=(ways[i][j]+cur*C(k-1,j-1)%mod)%mod;
        }
    }
    int res=0;
    dp[0][0]=1;
    for(int j=0;j<=sz-1;j++) sum[0][j]=1;
    for(int i=1;i<=n;i++)
    {
        for(int j=l[i];j<r[i];j++)
        {
            int cnt=0;
            for(int k=i;k>=1;k--)
            {
                if(val[l[k]]<=val[j]&&val[j+1]<=val[r[k]]);
                else cnt++;
                dp[i][j]=(dp[i][j]+sum[k-1][j-1]*ways[j][i-k+1-cnt]%mod)%mod;
            }
        }
        for(int j=1;j<=sz-1;j++)
        {
            sum[i][j]=(sum[i][j-1]+dp[i][j])%mod;
        }
        res=(res+sum[i][sz-1])%mod;
    }
    cout<<res;
}

Compilation message

boat.cpp:34:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   34 | main()
      |      ^

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Incorrect 1742 ms 10452 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 1742 ms 10452 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 2296 KB Output is correct
2 Correct 21 ms 2304 KB Output is correct
3 Correct 21 ms 2304 KB Output is correct
4 Correct 22 ms 2304 KB Output is correct
5 Correct 21 ms 2296 KB Output is correct
6 Correct 22 ms 2424 KB Output is correct
7 Correct 23 ms 2428 KB Output is correct
8 Correct 22 ms 2304 KB Output is correct
9 Correct 24 ms 2424 KB Output is correct
10 Correct 23 ms 2432 KB Output is correct
11 Correct 20 ms 2296 KB Output is correct
12 Correct 20 ms 2432 KB Output is correct
13 Correct 20 ms 2296 KB Output is correct
14 Correct 20 ms 2304 KB Output is correct
15 Correct 21 ms 2296 KB Output is correct
16 Correct 12 ms 1792 KB Output is correct
17 Correct 11 ms 1792 KB Output is correct
18 Correct 12 ms 1792 KB Output is correct
19 Correct 13 ms 1792 KB Output is correct
20 Correct 12 ms 1792 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Incorrect 1742 ms 10452 KB Output isn't correct
2 Halted 0 ms 0 KB -