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Submission #576901

# Submission time Handle Problem Language Result Execution time Memory
576901 2022-06-13T17:59:52 Z aryan12 Event Hopping (BOI22_events) C++17
100 / 100
 460 ms 43672 KB 
#include <bits/stdc++.h>
using namespace std;
#define int long long

mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());

const int N = 1e5 + 5, INF = 1e15;
int s[N], e[N];
int dp[20][N];
vector<pair<int, int> > seg(N * 8, {INF, -1});

void update(int l, int r, int pos, int qpos, pair<int, int> qval)
{
	if(l == r)
	{
		seg[pos] = min(seg[pos], qval);
		return;
	}
	int mid = (l + r) >> 1;
	if(qpos <= mid) update(l, mid, pos * 2, qpos, qval);
	else 			update(mid + 1, r, pos * 2 + 1, qpos, qval);
	seg[pos] = min(seg[pos * 2], seg[pos * 2 + 1]);
}

pair<int, int> query(int l, int r, int pos, int ql, int qr)
{
	if(ql > r || l > qr) return {INF, -1};
	if(ql <= l && r <= qr) return seg[pos];
	int mid = (l + r) >> 1;
	return min(query(l, mid, pos * 2, ql, qr), query(mid + 1, r, pos * 2 + 1, ql, qr));
}

void Solve() 
{
	int n, q;
	cin >> n >> q;
	map<int, int> cc;
	for(int i = 1; i <= n; i++)
	{
		cin >> s[i] >> e[i];
		cc[s[i]]++;
		cc[e[i]]++;
	}
	int cnt = 0;
	for(auto i: cc)
	{
		cc[i.first] = ++cnt;
	}
	for(int i = 1; i <= n; i++)
	{
		s[i] = cc[s[i]];
		e[i] = cc[e[i]];
		update(1, cnt, 1, e[i], {s[i], i});
	}
	for(int i = 1; i <= n; i++)
	{
		pair<int, int> res = query(1, cnt, 1, s[i], e[i]);
		if(res.first >= s[i]) dp[0][i] = -1;
		else 				  dp[0][i] = res.second;
	}
	for(int i = 1; i <= 19; i++)
	{
		for(int j = 1; j <= n; j++)
		{
			if(dp[i - 1][j] == -1) dp[i][j] = -1;
			else 				   dp[i][j] = dp[i - 1][dp[i - 1][j]];
		}
	}
	while(q--)
	{
		int qs, qe;
		cin >> qs >> qe;
		if(qs == qe)
		{
			cout << "0\n";
			continue;
		}
		if(e[qs] > e[qe])
		{
			cout << "impossible\n";
			continue;
		}
		if(s[qe] <= e[qs] && e[qs] <= e[qe])
		{
			cout << "1\n";
			continue;
		}
		int cur = qe, ans = 1;
		for(int i = 19; i >= 0; i--)
		{
			if(dp[i][cur] != -1 && s[dp[i][cur]] > e[qs])
			{
				cur = dp[i][cur];
				ans += (1 << i);
			}
		}
		if(dp[0][cur] == -1)
		{
			cout << "impossible\n";
		}
		else
		{
			cout << ans + 1 << "\n";
		}
	}
}

int32_t main() 
{
	auto begin = std::chrono::high_resolution_clock::now();
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int t = 1;
	// cin >> t;
	for(int i = 1; i <= t; i++) 
	{
		//cout << "Case #" << i << ": ";
		Solve();
	}
	auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n"; 
	return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 12884 KB Output is correct
2 Correct 195 ms 36936 KB Output is correct
3 Correct 235 ms 36844 KB Output is correct
4 Correct 272 ms 36904 KB Output is correct
5 Correct 266 ms 37600 KB Output is correct
6 Correct 232 ms 38348 KB Output is correct
7 Correct 284 ms 38448 KB Output is correct
8 Correct 254 ms 43628 KB Output is correct
9 Correct 247 ms 43628 KB Output is correct
10 Correct 265 ms 37252 KB Output is correct
11 Correct 253 ms 39824 KB Output is correct
12 Correct 131 ms 37324 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 12884 KB Output is correct
2 Correct 5 ms 12884 KB Output is correct
3 Correct 7 ms 13156 KB Output is correct
4 Correct 9 ms 13156 KB Output is correct
5 Correct 7 ms 13140 KB Output is correct
6 Correct 9 ms 13140 KB Output is correct
7 Correct 7 ms 13292 KB Output is correct
8 Correct 8 ms 13268 KB Output is correct
9 Correct 6 ms 13140 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 12884 KB Output is correct
2 Correct 5 ms 12884 KB Output is correct
3 Correct 7 ms 13156 KB Output is correct
4 Correct 9 ms 13156 KB Output is correct
5 Correct 7 ms 13140 KB Output is correct
6 Correct 9 ms 13140 KB Output is correct
7 Correct 7 ms 13292 KB Output is correct
8 Correct 8 ms 13268 KB Output is correct
9 Correct 6 ms 13140 KB Output is correct
10 Correct 6 ms 12928 KB Output is correct
11 Correct 6 ms 12920 KB Output is correct
12 Correct 6 ms 13140 KB Output is correct
13 Correct 6 ms 13140 KB Output is correct
14 Correct 8 ms 13140 KB Output is correct
15 Correct 6 ms 13140 KB Output is correct
16 Correct 7 ms 13268 KB Output is correct
17 Correct 7 ms 13268 KB Output is correct
18 Correct 6 ms 13140 KB Output is correct
19 Correct 41 ms 14752 KB Output is correct
20 Correct 37 ms 14540 KB Output is correct
21 Correct 43 ms 14924 KB Output is correct
22 Correct 39 ms 15080 KB Output is correct
23 Correct 33 ms 15052 KB Output is correct
24 Correct 30 ms 15136 KB Output is correct
25 Correct 41 ms 14764 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 12884 KB Output is correct
2 Correct 5 ms 12884 KB Output is correct
3 Correct 7 ms 13156 KB Output is correct
4 Correct 9 ms 13156 KB Output is correct
5 Correct 7 ms 13140 KB Output is correct
6 Correct 9 ms 13140 KB Output is correct
7 Correct 7 ms 13292 KB Output is correct
8 Correct 8 ms 13268 KB Output is correct
9 Correct 6 ms 13140 KB Output is correct
10 Correct 5 ms 12952 KB Output is correct
11 Correct 7 ms 12884 KB Output is correct
12 Correct 6 ms 13140 KB Output is correct
13 Correct 7 ms 13188 KB Output is correct
14 Correct 9 ms 13140 KB Output is correct
15 Correct 9 ms 13140 KB Output is correct
16 Correct 9 ms 13264 KB Output is correct
17 Correct 7 ms 13268 KB Output is correct
18 Correct 6 ms 13140 KB Output is correct
19 Correct 173 ms 36464 KB Output is correct
20 Correct 166 ms 36456 KB Output is correct
21 Correct 219 ms 36280 KB Output is correct
22 Correct 197 ms 38604 KB Output is correct
23 Correct 277 ms 42716 KB Output is correct
24 Correct 306 ms 42584 KB Output is correct
25 Correct 32 ms 30036 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 205 ms 36944 KB Output is correct
2 Correct 224 ms 36836 KB Output is correct
3 Correct 295 ms 36876 KB Output is correct
4 Correct 274 ms 43672 KB Output is correct
5 Correct 247 ms 37252 KB Output is correct
6 Correct 419 ms 43348 KB Output is correct
7 Correct 370 ms 43332 KB Output is correct
8 Correct 345 ms 43444 KB Output is correct
9 Correct 266 ms 42576 KB Output is correct
10 Correct 337 ms 43004 KB Output is correct
11 Correct 421 ms 42752 KB Output is correct
12 Correct 341 ms 42940 KB Output is correct

Subtask #6
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 12884 KB Output is correct
2 Correct 195 ms 36936 KB Output is correct
3 Correct 235 ms 36844 KB Output is correct
4 Correct 272 ms 36904 KB Output is correct
5 Correct 266 ms 37600 KB Output is correct
6 Correct 232 ms 38348 KB Output is correct
7 Correct 284 ms 38448 KB Output is correct
8 Correct 254 ms 43628 KB Output is correct
9 Correct 247 ms 43628 KB Output is correct
10 Correct 265 ms 37252 KB Output is correct
11 Correct 253 ms 39824 KB Output is correct
12 Correct 131 ms 37324 KB Output is correct
13 Correct 6 ms 12884 KB Output is correct
14 Correct 5 ms 12884 KB Output is correct
15 Correct 7 ms 13156 KB Output is correct
16 Correct 9 ms 13156 KB Output is correct
17 Correct 7 ms 13140 KB Output is correct
18 Correct 9 ms 13140 KB Output is correct
19 Correct 7 ms 13292 KB Output is correct
20 Correct 8 ms 13268 KB Output is correct
21 Correct 6 ms 13140 KB Output is correct
22 Correct 6 ms 12928 KB Output is correct
23 Correct 6 ms 12920 KB Output is correct
24 Correct 6 ms 13140 KB Output is correct
25 Correct 6 ms 13140 KB Output is correct
26 Correct 8 ms 13140 KB Output is correct
27 Correct 6 ms 13140 KB Output is correct
28 Correct 7 ms 13268 KB Output is correct
29 Correct 7 ms 13268 KB Output is correct
30 Correct 6 ms 13140 KB Output is correct
31 Correct 41 ms 14752 KB Output is correct
32 Correct 37 ms 14540 KB Output is correct
33 Correct 43 ms 14924 KB Output is correct
34 Correct 39 ms 15080 KB Output is correct
35 Correct 33 ms 15052 KB Output is correct
36 Correct 30 ms 15136 KB Output is correct
37 Correct 41 ms 14764 KB Output is correct
38 Correct 5 ms 12952 KB Output is correct
39 Correct 7 ms 12884 KB Output is correct
40 Correct 6 ms 13140 KB Output is correct
41 Correct 7 ms 13188 KB Output is correct
42 Correct 9 ms 13140 KB Output is correct
43 Correct 9 ms 13140 KB Output is correct
44 Correct 9 ms 13264 KB Output is correct
45 Correct 7 ms 13268 KB Output is correct
46 Correct 6 ms 13140 KB Output is correct
47 Correct 173 ms 36464 KB Output is correct
48 Correct 166 ms 36456 KB Output is correct
49 Correct 219 ms 36280 KB Output is correct
50 Correct 197 ms 38604 KB Output is correct
51 Correct 277 ms 42716 KB Output is correct
52 Correct 306 ms 42584 KB Output is correct
53 Correct 32 ms 30036 KB Output is correct
54 Correct 205 ms 36944 KB Output is correct
55 Correct 224 ms 36836 KB Output is correct
56 Correct 295 ms 36876 KB Output is correct
57 Correct 274 ms 43672 KB Output is correct
58 Correct 247 ms 37252 KB Output is correct
59 Correct 419 ms 43348 KB Output is correct
60 Correct 370 ms 43332 KB Output is correct
61 Correct 345 ms 43444 KB Output is correct
62 Correct 266 ms 42576 KB Output is correct
63 Correct 337 ms 43004 KB Output is correct
64 Correct 421 ms 42752 KB Output is correct
65 Correct 341 ms 42940 KB Output is correct
66 Correct 6 ms 12884 KB Output is correct
67 Correct 226 ms 36836 KB Output is correct
68 Correct 221 ms 36872 KB Output is correct
69 Correct 274 ms 36908 KB Output is correct
70 Correct 251 ms 37516 KB Output is correct
71 Correct 245 ms 38204 KB Output is correct
72 Correct 272 ms 38424 KB Output is correct
73 Correct 261 ms 43604 KB Output is correct
74 Correct 272 ms 43612 KB Output is correct
75 Correct 257 ms 37268 KB Output is correct
76 Correct 259 ms 39804 KB Output is correct
77 Correct 145 ms 37340 KB Output is correct
78 Correct 7 ms 12864 KB Output is correct
79 Correct 7 ms 13224 KB Output is correct
80 Correct 6 ms 13116 KB Output is correct
81 Correct 6 ms 13132 KB Output is correct
82 Correct 6 ms 13140 KB Output is correct
83 Correct 7 ms 13268 KB Output is correct
84 Correct 7 ms 13268 KB Output is correct
85 Correct 6 ms 13140 KB Output is correct
86 Correct 45 ms 14728 KB Output is correct
87 Correct 37 ms 14588 KB Output is correct
88 Correct 45 ms 14916 KB Output is correct
89 Correct 38 ms 14888 KB Output is correct
90 Correct 33 ms 15108 KB Output is correct
91 Correct 28 ms 15120 KB Output is correct
92 Correct 34 ms 14684 KB Output is correct
93 Correct 206 ms 36240 KB Output is correct
94 Correct 188 ms 36376 KB Output is correct
95 Correct 192 ms 36432 KB Output is correct
96 Correct 244 ms 38648 KB Output is correct
97 Correct 337 ms 42576 KB Output is correct
98 Correct 307 ms 42560 KB Output is correct
99 Correct 38 ms 29980 KB Output is correct
100 Correct 384 ms 43328 KB Output is correct
101 Correct 460 ms 43328 KB Output is correct
102 Correct 337 ms 43600 KB Output is correct
103 Correct 390 ms 42968 KB Output is correct
104 Correct 350 ms 42948 KB Output is correct
105 Correct 358 ms 42912 KB Output is correct
106 Correct 212 ms 35476 KB Output is correct
107 Correct 321 ms 37048 KB Output is correct
108 Correct 218 ms 37164 KB Output is correct
109 Correct 241 ms 37052 KB Output is correct
110 Correct 335 ms 43220 KB Output is correct
111 Correct 337 ms 43192 KB Output is correct