Submission #415854

#	Time	Username	Problem	Language	Result	Execution time	Memory
415854		grt	Boat (APIO16_boat)	C++17	9 / 100	2105 ms	215160 KiB

boat

#include <bits/stdc++.h>
#define ST first
#define ND second
#define PB push_back

using namespace std;
using ll = long long;
using pi = pair<int,int>;
using vi = vector<int>;

const int nax = 500 + 10, mod = 1e9 + 7;
int n, mx;
map<int, int>dp, dp2;
int a[nax], b[nax];

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cin >> n;
	for(int i = 1; i <= n; ++i) {
		cin >> a[i] >> b[i];
	}
	dp[0] = 1;
	for(int i = 1; i <= n; ++i) {
		int sum = 0;
		for(auto x : dp) sum = (sum + x.ND) % mod;
		dp2 = dp;
		auto it = dp.end();
		for(int j = b[i]; j >= a[i]; --j) {
			while(it != dp.begin() && (*prev(it)).ST >= j) {
				it = prev(it);
				sum = (sum - (*it).ND) % mod;
			}
			dp2[j] = (dp2[j] + sum) % mod;
		}
		dp = dp2;
	}
	int ans = 0;
	for(auto x : dp) ans = (ans + x.ND) % mod;
	ans--;
	if(ans < 0) ans += mod;
	cout << ans;
		
}

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