Submission #203906

#	Time	Username	Problem	Language	Result	Execution time	Memory
203906		Segtree	Boat (APIO16_boat)	C++14	31 / 100	1443 ms	524292 KiB

boat

#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
typedef long long ll;
#define chmin(a,b) a=min(a,b)
#define chmax(a,b) a=max(a,b)
#define rep(i,n) for(int i=0;i<n;i++)
#define mod 1000000007
#define mad(a,b) a=(a+b)%mod
#define N 510
#define X 1000010
vector<ll> dp[N];
ll a[N],b[N];
int main(){
	ll n; cin>>n;
	a[0]=b[0]=0;
	dp[0].push_back(1);
	for(int i=1;i<=n;i++){
		cin>>a[i]>>b[i];
		for(int j=a[i];j<=b[i];j++)dp[i].push_back(0);
		for(int j=0;j<i;j++){
			for(int k=a[j];k<=b[j];k++){
				if(k<a[i])mad(dp[i][0],dp[j][k-a[j]]);
				else if(k<b[i])mad(dp[i][k+1-a[i]],dp[j][k-a[j]]);
			}
		}
		for(int j=a[i]+1;j<=b[i];j++)mad(dp[i][j-a[i]],dp[i][j-1-a[i]]);
	}
	ll ans=0;
	for(int i=1;i<=n;i++){
		for(int j=a[i];j<=b[i];j++){
			//cout<<i<<" "<<j<<" "<<dp[i][j-a[i]]<<endl;
			mad(ans,dp[i][j-a[i]]);
		}
	}
	cout<<ans<<endl;
}

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