oj.uz

Submission #210494

# Submission time Handle Problem Language Result Execution time Memory
210494 2020-03-17T14:12:06 Z hanagasumi Railway Trip (JOI17_railway_trip) C++17
20 / 100
 2000 ms 13352 KB 
#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <deque>
#include <map>
#include <set>
#include <complex>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <chrono>

#define ft first
#define sc second
#define pb push_back
#define len(v) (int)v.size()
#define int ll

using namespace std;
typedef long long ll;
typedef long double ld;

int inf = 1e9 + 100;

signed main() {
	#ifdef PC
		freopen("in.txt", "r", stdin);
		freopen("out.txt", "w", stdout);
	#endif	
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);

	int n, k, q;
	cin >> n >> k >> q;
	vector<int> l(n);
	vector<vector<int>> g(n);
	for (int i = 0; i < n; i++) {
		cin >> l[i];
	}

	vector<int> pred(n, -1);
	vector<int> nxt(n, n);
	vector<pair<int, int>> have;
	for (int i = 0; i < n; i++) {
		while(len(have) > 0 && have.back().ft <= l[i]) 
			have.pop_back();
		if(len(have) > 0) 
			pred[i] = have.back().sc;
		have.pb({l[i], i});
	}
	have.clear();
	for (int i = n - 1; i >= 0; i--) {
		while(len(have) > 0 && have.back().ft <= l[i]) 
			have.pop_back();
		if(len(have) > 0)
			nxt[i] = have.back().sc;
		have.pb({l[i], i});
	}

	int cnt = 0;
	for (int i = 0; i < n; i++) {
		if(i < n - 1) 
			g[i].pb(i + 1);
		int now = i - 1;
		while(1) {
			if(now < 0) 
				break;
			g[i].pb(now);
			cnt++;
			if(l[now] >= l[i]) 
				break;
			now = pred[now];
		}
		now = i + 1;
		while(1) {
			if(now >= n) 
				break;
			g[i].pb(now);
			cnt++;
			if(l[now] >= l[i]) 
				break;
			now = nxt[now];
		}
	}
	if(cnt > 5 * n) 
		return -1;

	for (int i = 0; i < q; i++) {		
		int a, b;
		cin >> a >> b;
		a--, b--;

		vector<int> dst(n, inf);
		dst[a] = 0;
		deque<int> q;
		q.pb(a);
		while(len(q) > 0) {
			auto now = q.front();
			q.pop_front();
			for (auto x : g[now]) {
				if(dst[x] != inf) 
					continue;
				dst[x] = dst[now] + 1;
				q.pb(x);
			}
		}
		cout << dst[b] - 1 << '\n';
	}

	return 0;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 376 KB Output is correct
2 Correct 5 ms 376 KB Output is correct
3 Correct 5 ms 376 KB Output is correct
4 Correct 5 ms 376 KB Output is correct
5 Correct 5 ms 376 KB Output is correct
6 Correct 5 ms 376 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 5 ms 376 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 504 KB Output is correct
2 Correct 213 ms 12024 KB Output is correct
3 Correct 250 ms 12408 KB Output is correct
4 Correct 270 ms 12536 KB Output is correct
5 Correct 287 ms 12664 KB Output is correct
6 Correct 287 ms 12920 KB Output is correct
7 Correct 324 ms 13276 KB Output is correct
8 Correct 99 ms 10744 KB Output is correct
9 Correct 99 ms 12404 KB Output is correct
10 Correct 102 ms 11764 KB Output is correct
11 Correct 184 ms 11896 KB Output is correct
12 Correct 183 ms 11900 KB Output is correct
13 Correct 182 ms 11900 KB Output is correct
14 Correct 183 ms 11896 KB Output is correct
15 Correct 185 ms 11896 KB Output is correct
16 Correct 188 ms 11896 KB Output is correct
17 Correct 331 ms 13352 KB Output is correct
18 Correct 327 ms 13304 KB Output is correct
19 Correct 179 ms 12812 KB Output is correct

Subtask #3
0 / 25.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2092 ms 12408 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 55.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2097 ms 13304 KB Time limit exceeded
2 Halted 0 ms 0 KB -