Submission #69274

#	Time	Username	Problem	Language	Result	Execution time	Memory
69274		FedericoS	Boat (APIO16_boat)	C++14	0 / 100	2073 ms	164016 KiB

boat

#include <iostream>
#include <map>
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> pll;

ll M=1000000007;
int N;
ll X[505],Y[505];
map<ll,ll> S;
map<pll,ll> DP;
ll ans;
map<ll,ll> R;

ll somma(ll a){
	ll res=0;
	for(ll i=a;i<10000;i++)
		res=(res+R[i])%M;
	return res;
}

void aggiungi(ll a, ll b){
	R[a]=(R[a]+b)%M;
}

int main(){

	cin>>N;
	for(int i=0;i<N;i++)
		cin>>X[i]>>Y[i];

	for(int i=N-1;i>=0;i--)
		for(ll j=X[i];j<=Y[i];j++){
			DP[{i,j}]=(somma(j+1)+1)%M;
			aggiungi(j,DP[{i,j}]);
			//cout<<i<<" "<<j<<" "<<DP[{i,j}]<<endl;
		}

	//for(int i=0;i<10;i++)cout<<i<<" "<<S[i]<<endl;

	for(int i=0;i<N;i++)
		ans=(ans+DP[{i,X[i]}])%M;
	cout<<ans;

}
/*
3
1 1
2 2
3 3
*/

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