oj.uz

답안 #549083

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
549083 2022-04-15T05:57:31 Z LucaDantas Railway Trip (JOI17_railway_trip) C++17
30 / 100
 1319 ms 524288 KB 
#include <bits/stdc++.h>
using namespace std;

constexpr int maxn = 1e5+10;

int a[maxn], l[maxn][2], r[maxn][2], dist[2][maxn], mark[maxn], seen[maxn], cnt;

vector<int> pos[maxn];

int d(int x, int y, int k) {
	// se x==y ele retorna -1 e é pra retornar isso mesmo
	if(x > y) swap(x, y);
	return lower_bound(pos[k].begin(), pos[k].end(), y) - lower_bound(pos[k].begin(), pos[k].end(), x) - 1;
}

vector<int> reached[2][maxn];

void dijkstra(int s, int k) {
	++cnt;
	dist[k][s] = 0;
	seen[s] = cnt;
	priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> q;
	q.push({0, s});
	while(q.size()) {
		int u = q.top().second; q.pop();
		if(mark[u] == cnt) continue;
		mark[u] = cnt;
		reached[k][a[u]].push_back(u);

		int d = dist[k][u];
		for(auto [v, w] : {make_pair(l[u][0], l[u][1]), make_pair(r[u][0], r[u][1])}) {
			if(seen[v] < cnt || dist[k][v] > d + w) {
				seen[v] = cnt;
				dist[k][v] = d+w;
				q.push({d+w, v});
			}
		}
	}
}

int main() {
	int n, k, q; scanf("%d %d %d", &n, &k, &q);
	for(int i = 0; i < n; i++) {
		scanf("%d", a+i);
		for(int j = 0; j <= a[i]; j++)
			pos[j].push_back(i);
	}

	for(int i = 0; i < n; i++) {
		if(a[i] == k) { l[i][0] = i; l[i][1] = 0; continue; }
		l[i][0] = i-1; l[i][1] = 1;
		while(a[l[i][0]] <= a[i]) {
			l[i][1] = (a[l[i][0]] == a[i] ? l[l[i][0]][1] : 0) + 1;
			l[i][0] = l[l[i][0]][0];
		}
	}
	
	for(int i = n-1; i >= 0; i--) {
		if(a[i] == k) { r[i][0] = i, r[i][1] = 0; continue; }
		r[i][0] = i+1; r[i][1] = 1;
		while(a[r[i][0]] <= a[i]) {
			r[i][1] = (a[r[i][0]] == a[i] ? r[r[i][0]][1] : 0) + 1;
			r[i][0] = r[r[i][0]][0];
		}
	}

	while(q--) {
		int x, y; scanf("%d %d", &x, &y);
		--x, --y;

		dijkstra(x, 0); dijkstra(y, 1);

		int ans = 0x3f3f3f3f;

		for(int lvl = 1; lvl <= k; lvl++) {
			for(int x : reached[0][lvl]) for(int y : reached[1][lvl])
				ans = min(ans, dist[0][x] + dist[1][y] + d(x, y, lvl));
			reached[0][lvl].clear(), reached[1][lvl].clear();
		}

		printf("%d\n", ans);
	}
}

Compilation message

railway_trip.cpp: In function 'int main()':
railway_trip.cpp:42:20: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |  int n, k, q; scanf("%d %d %d", &n, &k, &q);
      |               ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
railway_trip.cpp:44:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |   scanf("%d", a+i);
      |   ~~~~~^~~~~~~~~~~
railway_trip.cpp:68:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |   int x, y; scanf("%d %d", &x, &y);
      |             ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 7380 KB Output is correct
2 Correct 5 ms 7380 KB Output is correct
3 Correct 4 ms 7380 KB Output is correct
4 Correct 4 ms 7380 KB Output is correct
5 Correct 4 ms 7380 KB Output is correct
6 Correct 4 ms 7380 KB Output is correct
7 Correct 4 ms 7380 KB Output is correct
8 Correct 4 ms 7380 KB Output is correct
9 Correct 5 ms 7348 KB Output is correct

Subtask #2
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 10324 KB Output is correct
2 Correct 20 ms 13328 KB Output is correct
3 Correct 22 ms 15528 KB Output is correct
4 Correct 32 ms 22132 KB Output is correct
5 Correct 50 ms 32896 KB Output is correct
6 Correct 339 ms 224120 KB Output is correct
7 Runtime error 1315 ms 524288 KB Execution killed with signal 9
8 Halted 0 ms 0 KB -

Subtask #3
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 234 ms 15080 KB Output is correct
2 Correct 218 ms 14076 KB Output is correct
3 Correct 231 ms 15472 KB Output is correct
4 Correct 228 ms 15560 KB Output is correct
5 Correct 242 ms 15732 KB Output is correct
6 Correct 235 ms 16128 KB Output is correct
7 Correct 237 ms 16424 KB Output is correct
8 Correct 142 ms 12488 KB Output is correct
9 Correct 118 ms 12352 KB Output is correct
10 Correct 321 ms 12344 KB Output is correct
11 Correct 387 ms 12444 KB Output is correct
12 Correct 399 ms 12304 KB Output is correct
13 Correct 402 ms 12472 KB Output is correct
14 Correct 400 ms 12304 KB Output is correct
15 Correct 614 ms 12316 KB Output is correct
16 Correct 608 ms 14204 KB Output is correct

Subtask #4
0 / 55.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 1319 ms 524288 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -