oj.uz

Submission #702578

# Submission time Handle Problem Language Result Execution time Memory
702578 2023-02-24T13:21:10 Z Chal1shkan Event Hopping (BOI22_events) C++14
0 / 100
 94 ms 5076 KB 
# 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 t[maxn * 4];

void update (int pos, int x, int v = 1, int tl = 1, int tr = n + n)
{
	if (tl == tr)
	{
		t[v] = max(t[v], x);
		return;
	}
	else
	{
		int tm = (tl + tr) >> 1;
		if (pos <= tm)
		{
			update(pos, x, v * 2, tl, tm);
		}
		else
		{
			update(pos, x, v * 2 +1, tm + 1, tr);
		}
		t[v] = max(t[v * 2], t[v * 2 + 1]);
	}
}

int get (int l, int r, int v = 1, int tl = 1, int tr = n + n)
{
	if (tr < l || r < tl) return -1;
	if (l <= tl && tr <= r) return t[v];
	int tm = (tl + tr) >> 1;
	return max(get(l, r, v * 2, tl, tm), get(l, r, v * 2 + 1, tm + 1, tr));
}

int f (int id1, int id2)
{
	int ans = 0;
	id1 = pos[id1], id2 = pos[id2];
	while (id1 < id2)
	{
		int pos = get(1, p[id1].ff.ss);
		if (pos == -1 || id1 == pos)
		{
			ans = inf;
			break;
		}
		if (pos > id2)
		{
			if (p[id1].ff.ss >= p[id2].ff.ff)
			{
				ans++;
				id1 = id2;
				break;
			}
		}
		id1 = pos;
		ans++;
	}
	if (id1 > id2)
	{
		ans = inf;
	}
	return ans;
}
 
void ma1n (/* SABR */)
{
	memset(t, -1, sizeof(t));
	cin >> n >> q;
	vector <int> v;
	for (int i = 1; i <= n; ++i)
	{
		cin >> p[i].ff.ff >> p[i].ff.ss;
		p[i].ss = i;
		v.pb(p[i].ff.ff);
		v.pb(p[i].ff.ss);
	}
	sort(v.begin(), v.end());
	auto ittttt = unique(v.begin(), v.end());
  	v.resize(distance(v.begin(), ittttt));
	for (int i = 1; i <= n; ++i)
	{
		p[i].ff.ff = lower_bound(v.begin(), v.end(), p[i].ff.ff) - v.begin() + 1;
		p[i].ff.ss = lower_bound(v.begin(), v.end(), p[i].ff.ss) - v.begin() + 1;
	}
	sort(p + 1, p + 1 + n, cmp);
	for (int i = 1; i <= n; ++i)
	{
		update(p[i].ff.ff, i);
	}
	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 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1876 KB Output is correct
2 Incorrect 78 ms 5076 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1904 KB Output is correct
2 Correct 1 ms 1876 KB Output is correct
3 Correct 9 ms 1876 KB Output is correct
4 Correct 2 ms 1908 KB Output is correct
5 Incorrect 2 ms 1876 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1904 KB Output is correct
2 Correct 1 ms 1876 KB Output is correct
3 Correct 9 ms 1876 KB Output is correct
4 Correct 2 ms 1908 KB Output is correct
5 Incorrect 2 ms 1876 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1904 KB Output is correct
2 Correct 1 ms 1876 KB Output is correct
3 Correct 9 ms 1876 KB Output is correct
4 Correct 2 ms 1908 KB Output is correct
5 Incorrect 2 ms 1876 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 94 ms 4628 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1876 KB Output is correct
2 Incorrect 78 ms 5076 KB Output isn't correct
3 Halted 0 ms 0 KB -