Submission #970611

#	Time	Username	Problem	Language	Result	Execution time	Memory
970611		starchan	Boat (APIO16_boat)	C++17	9 / 100	264 ms	41756 KiB

boat

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define in array<int, 2>
#define pb push_back
#define pob pop_back
#define INF (int)1e17
#define fast() ios_base::sync_with_stdio(false); cin.tie(NULL)

const int mod = 1e9+7; 
const int MX = 5e3+5;

int dp[MX][2*MX];
int ans[2*MX];

signed main()
{
	fast();
	vector<int> v;
	int n;
	cin >> n;
	n++;
	vector<in> a(n+1);
	for(int i = 1; i < n; i++)
	{
		cin >> a[i][0] >> a[i][1]; 
		v.pb(a[i][0]); v.pb(++a[i][1]);
	}
	a[n][0] = 1e9+1; a[n][1] = 1e9+2;
	v.pb(a[n][0]); v.pb(a[n][1]);
	sort(v.begin(), v.end());
	vector<int> CC; CC.pb(v[0]);
	for(auto x: v)
	{
		if(x != CC.back())
			CC.pb(x);
	}
	for(int i = 1; i <= n; i++)
	{
		a[i][0] = lower_bound(CC.begin(), CC.end(), a[i][0])-CC.begin();
		a[i][1] = lower_bound(CC.begin(), CC.end(), a[i][1])-CC.begin();
	}

	int M = CC.size();
	//We are interested in dp[n][MM]
	for(int i = 1; i <= n; i++)
	{
		for(int j = a[i][0]; j < a[i][1]; j++)
		{
			dp[i][j] = 1;
			for(int d = 0; d < j; d++)
			{
				dp[i][j]+=ans[d];
				dp[i][j]%=mod;
			}
			dp[i][j]*=(CC[j+1]-CC[j]); dp[i][j]%=mod;
		}
		for(int j = a[i][0]; j < a[i][1]; j++)
		{
			ans[j]+=dp[i][j];
			ans[j]%=mod;
		}
	}
	dp[n][M-2]+=(mod-1); dp[n][M-2]%=mod;
	cout << dp[n][M-2] << "\n";
	return 0;
}	

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