Submission #702555

#	Time	Username	Problem	Language	Result	Execution time	Memory
702555		Chal1shkan	Event Hopping (BOI22_events)	C++14	10 / 100	1575 ms	1868 KiB

events

# include <bits/stdc++.h>

# define pb push_back
# define ff first
# define ss second
# define nl "\n"
# define sz(x) ((int)(x).size())
# define deb(x) cerr << #x  << " = " << x << endl; 

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

const ll maxn = 1e5 + 25;
const ll inf = 2e9 + 0;
const ll mod = 998244353;
const ll dx[] = {-1, 1, 0, 0};
const ll dy[] = {0, 0, -1, 1};

using namespace std;

int n, q, pos[maxn];
pair <pair <int, int>, int> p[maxn];


bool cmp (pair <pair <int, int>, int> a, pair <pair <int, int>, int> b)
{
	if (a.ff.ss != b.ff.ss)
	{
		return a.ff.ss < b.ff.ss;
	}
	else
	{
		return a.ff.ff < b.ff.ff;
	}
}

int f (int id1, int id2)
{
	int ans = 0;
	id1 = pos[id1], id2 = pos[id2];
	while (id1 < id2)
	{
		int pos = -1;
		for (ll j = id1 + 1; j <= id2; ++j)
		{
			if (p[id1].ff.ss >= p[j].ff.ff)
			{
				pos = j;
			}
		}
		if (pos == -1)
		{
			ans = inf;
			break;
		}
		id1 = pos;
		ans++;
	}
	if (id1 > id2)
	{
		ans = inf;
	}
	return ans;
}

void ma1n (/* SABR */)
{
	cin >> n >> q;
	for (int i = 1; i <= n; ++i)
	{
		cin >> p[i].ff.ff >> p[i].ff.ss;
		p[i].ss = i;
	}
	sort(p + 1, p + 1 + n, cmp);
	for (int i = 1; i <= n; ++i)
	{
		pos[p[i].ss] = i;
	}
	if (n <= 5000)
	{
		while (q--)
		{
			int id1, id2;
			cin >> id1 >> id2;
			int ans = f(id1, id2);
			if (ans != inf)
			{
				cout << ans << nl;
			}
			else
			{
				cout << "impossible" << nl;
			}
		}
	}
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
//    freopen("angry.in", "r", stdin);
//    freopen("angry.out", "w", stdout);
    int ttt = 1;
//  cin >> ttt;
    for (int test = 1; test <= ttt; ++test)
    {
//      cout << "Case " << test << ":" << ' ';
        ma1n();
    }
    return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30