Submission #388952

#	Time	Username	Problem	Language	Result	Execution time	Memory
388952		prvocislo	Boat (APIO16_boat)	C++17	9 / 100	7 ms	4340 KiB

boat

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <queue>
#include <map>
#include <set>
#include <iomanip>
typedef long long ll;
using namespace std;

const ll mod = 1e9 + 7;
void upd(ll& a, const ll& b) { a = (a + b) % mod; }
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n;
	cin >> n;
	vector<int> a(n + 1), b(n + 1);
	for (int i = 1; i <= n; i++) cin >> a[i] >> b[i];
	set<int>s(a.begin(), a.end());
	for (int i = 0; i <= n; i++) s.insert(b[i] + 1);
	vector<int> v(s.begin(), s.end());
	vector<vector<ll> > dp(n + 1, vector<ll>(v.size(), 0));
	dp[0][0] = 1;
	for (int i = 1; i <= n; i++)
	{
		dp[i] = dp[i - 1];
		ll sum = 0;
		for (int j = 0; j < v.size() - 1; j++)
		{
			if (a[i] <= v[j] && v[j] <= b[i])
			{
				upd(dp[i][j], (sum * 1ll * (v[j + 1] - v[j])) % mod);
			}
			upd(sum, dp[i - 1][j]);
		}
	}
	ll ans = 0;
	for (int j = 1; j < v.size(); j++) upd(ans, dp[n][j]);
	cout << ans << "\n";
	return 0;
}

Compilation message (stderr)

boat.cpp: In function 'int main()':
boat.cpp:31:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |   for (int j = 0; j < v.size() - 1; j++)
      |                   ~~^~~~~~~~~~~~~~
boat.cpp:41:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |  for (int j = 1; j < v.size(); j++) upd(ans, dp[n][j]);
      |                  ~~^~~~~~~~~~

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