Submission #251788

#	Time	Username	Problem	Language	Result	Execution time	Memory
251788		hackermub	Boat (APIO16_boat)	C++17	9 / 100	392 ms	524292 KiB

boat

#include<bits/stdc++.h>
using namespace std;
 
#define int long long
#define pii pair<int,int>
#define fi first
#define se second
#define all(v) v.begin(),v.end()
#define pb push_back
#define sz(v) (int)v.size()
const int MOD = 1e9+7;
const int64_t INF = 1e18;

int32_t main(){
    ios_base::sync_with_stdio(false);cin.tie();
    //If you hack my code , You are gay;
    int n;
    cin>>n;
    vector<int> L(n),R(n);
    vector<int> v={0};
    for(int i=0;i<n;i++){
        cin>>L[i]>>R[i];
        for(int j=L[i];j<=R[i];j++){
            v.push_back(j);
        }
    }
    sort(all(v));
    v.erase(unique(all(v)),v.end());
    for(int i=0;i<n;i++){
        L[i] = lower_bound(all(v),L[i])-v.begin();
        R[i] = lower_bound(all(v),R[i])-v.begin();
        //cout<<L[i]<<" "<<R[i]<<"\n";
    }
    vector<vector<int>> dp(n+1,vector<int>(sz(v)+1,0)),sum(n+1,vector<int>(sz(v)+1,0));
    dp[0][0]=1;
    for(int i=0;i<sz(v);i++) sum[0][i] = 1;
    for(int i=1;i<=n;i++){
        for(int j=L[i-1];j<=R[i-1];j++){
            dp[i][j] = (dp[i][j] + sum[i-1][j-1])%MOD;
        }
        sum[i][0] = 1;
        for(int j=1;j<sz(v);j++){
            sum[i][j] = (dp[i][j] + sum[i-1][j] + sum[i][j-1] - sum[i-1][j-1])%MOD;
        }
    }
    cout<<(sum[n][sz(v)-1]-1+MOD)%MOD;
    return 0;
}

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