Submission #1188561

#	Time	Username	Problem	Language	Result	Execution time	Memory
1188561		Malix	Boat (APIO16_boat)	C++20	36 / 100	2094 ms	8264 KiB

boat

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef pair<int,int> pi;
typedef vector<pi> pii;
typedef tuple<ll,ll,ll> ti;
typedef vector<ll> li;
typedef vector<li> lii;
 
#define REP(i,a,b) for(int i=a;i<b;i++)
#define F first
#define S second
#define PB push_back
#define LSOne(s) ((s)&(-s))
 
ll INF=1000000000000000010;
int inf=1e9+10;
ll M=1e9+7;

ll md(ll x){
    ll b=M-2;
    ll ans=1;
    while(b){
        if(b&1){
            ans*=x;
            ans%=M;
        }
        b/=2;
        x=(x*x)%M;
    }
    return ans;
}

int main() {   
// ios::sync_with_stdio(0);
// cin.tie(0);
    int n;cin>>n;
    vector<pair<ll,ll>> a(n);
    set<ll> tmp;
    vector<ll> arr;
    REP(i,0,n){
        cin>>a[i].F>>a[i].S;
        a[i].S++;
        tmp.insert(a[i].F);
        tmp.insert(a[i].S);
    }
    for(auto u:tmp)arr.PB(u);
    sort(arr.begin(),arr.end());
    arr.back();
    arr.PB(arr.back()+1);
    int m=arr.size()-1;
    vector<vector<ll>> dp(n,vector<ll>(m,0)),sm(n,vector<ll>(m,0));
    REP(i,0,n){
        REP(j,0,m){
            if(arr[j]<a[i].F)continue;
            if(arr[j]==a[i].S)break;
            dp[i][j]=arr[j+1]-arr[j];
            sm[i][j]=1;
            if(j!=0)REP(k,0,i){
                sm[i][j]+=dp[k][j-1];
                sm[i][j]%=M;
                dp[i][j]+=dp[k][j-1]*(arr[j+1]-arr[j]);
                dp[i][j]%=M;
            }
            ll N=arr[j+1]-arr[j]-1;
            ll K=1;
            ll tot=N;
            for(int k=i-1;k>=0;k--){
                if(sm[k][j]==0)continue;
                N++;K++;
                tot*=N;
                tot%=M;
                tot*=md(K);
                tot%=M;
                dp[i][j]+=tot*sm[k][j];
                dp[i][j]%=M;
            }
        }
        REP(j,1,m)dp[i][j]+=dp[i][j-1];
    }
    ll ans=0;
    REP(i,0,n){
        ans+=dp[i][m-1];
        ans%=M;
    }
    cout<<ans;
}

• Subtask 1: 9 / 9
• Subtask 2: 0 / 22
• Subtask 3: 27 / 27
• Subtask 4: 0 / 42