Submission #362526

#	Time	Username	Problem	Language	Result	Execution time	Memory
362526		flappybird	Boat (APIO16_boat)	C++14	9 / 100	2081 ms	524292 KiB

boat

#include <bits/stdc++.h>
using namespace std;
#define MAX 510
#define all(v) v.begin(), v.end()
#define ln '\n'
#define MOD 1000000007
#define INF 210000000000
#define pb push_back
#define abs(x) (((x)>0)?(x):(-(x)))
#define len(x) ((x).second-(x).first)
typedef long long ll;
vector<ll> dp[MAX], sum[MAX];
ll A[MAX], B[MAX];
pair<ll, ll> s[MAX];
int main(void) {
	ios::sync_with_stdio(false);
	cin.tie(0);
	ll N;
	cin >> N;
	ll i, j, k;
	for (i = 1; i <= N; i++) cin >> A[i] >> B[i], dp[i].pb(0), sum[i].pb(0);
	for (i = A[1]; i <= B[1]; i++) {
		dp[1].pb(1);
		sum[1].pb(0);
		sum[1][i - A[1] + 1] = (sum[1][i - A[1]] + dp[1][i - A[1] + 1]) % MOD;
	}
	s[1] = { A[1], 1 };
	ll it;
	for (i = 2; i <= N; i++) {
		for (j = A[i]; j <= B[i]; j++) {
			dp[i].pb(1), sum[i].pb(0);
			for (it = 1; it <= i - 1; it++) {
				k = s[it].second;
				if (j - A[k] <= 0) break;
				dp[i][j - A[i] + 1] += sum[k][min(j - A[k], (ll)(sum[k].size() - 1))];
				dp[i][j - A[i] + 1] %= MOD;
			}
			sum[i][j - A[i] + 1] = (sum[i][j - A[i]] + dp[i][j - A[i] + 1]) % MOD;
		}
		for (j = 1; j < i; j++) {
			if (s[j].first > A[i]) break;
		}
		pair<ll, ll> tmp = { A[i], i }, t;
		k = j;
		for (j = k; j <= i - 1; j++) {
			t = s[j];
			s[j] = tmp;
			tmp = t;
		}
		s[i] = tmp;
	}
	ll ans = 0;
	for (i = 1; i <= N; i++) ans += sum[i][sum[i].size() - 1];
	ans %= MOD;
	while (ans < 0) ans += MOD;
	cout << ans << ln;
	return 0;
}

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