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답안 #201505

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
201505 2020-02-10T19:34:23 Z Noam527 Olympic Bus (JOI20_ho_t4) C++17
100 / 100
 96 ms 3812 KB 
#include <bits/stdc++.h>
#define finish(x) return cout << x << endl, 0
typedef long long ll;
typedef long double ldb;
const int md = 1e9 + 7;
const ll inf = 4e16;
const int OO = 0;
const int OOO = 1;
using namespace std;

struct edge {
	int v, w, i;
	edge() {}
	edge(int vv, int ww, int ii) {
		v = vv;
		w = ww;
		i = ii;
	}
	bool operator < (const edge &a) const {
		return w > a.w;
	}
};

int n, m;
vector<pair<int, int>> e;
vector<int> c, d;
vector<vector<edge>> g;
vector<ll> cost;

vector<int> dist, to;
vector<int> path1, path2;
vector<int> P1, P2; // P1[i] == j if edge i is used as the jth edge (1-indexed), 0 otherwise

// floyd warshall; normal, without p1, without p2
int fw[202][202], fwp1[202][202], fwp2[202][202];

vector<int> dijkstra(int s, int t) {
	for (auto &i : dist)
		i = -1;
	priority_queue<edge> q;
	q.push(edge(s, 0, -1));
	while (q.size()) {
		edge x = q.top();
		q.pop();
		if (dist[x.v] != -1) continue;
		dist[x.v] = x.w;
		to[x.v] = x.i;
		for (const auto &i : g[x.v])
			if (dist[i.v] == -1)
				q.push(edge(i.v, x.w + i.w, i.i));
	}
	if (dist[t] == -1) return{};
	vector<int> res;
	int cur = t;
	while (cur != s) {
		res.push_back(to[cur]);
		cur = e[to[cur]].first;
	}
	reverse(res.begin(), res.end());
	return res;
}

int main() {
	ios::sync_with_stdio(0), cin.tie(0);
	cin >> n >> m;
	e.resize(m), c.resize(m), d.resize(m);
	g.resize(n);
	cost.resize(m, 0);
	dist.resize(n), to.resize(n);
	P1.resize(m, 0), P2.resize(m, 0);

	for (int i = 0; i < m; i++) {
		cin >> e[i].first >> e[i].second >> c[i] >> d[i];
		e[i].first--, e[i].second--;
		g[e[i].first].push_back(edge(e[i].second, c[i], i));
	}

	path1 = dijkstra(0, n - 1), path2 = dijkstra(n - 1, 0);
	for (int i = 0; i < path1.size(); i++)
		P1[path1[i]] = i + 1;
	for (int i = 0; i < path2.size(); i++)
		P2[path2[i]] = i + 1;

	for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) {
		if (i != j)
			fw[i][j] = fwp1[i][j] = fwp2[i][j] = md;
		else
			fw[i][j] = fwp1[i][j] = fwp2[i][j] = 0;
	}
	for (int i = 0; i < m; i++) {
		fw[e[i].first][e[i].second] = min(fw[e[i].first][e[i].second], c[i]);
		if (!P1[i])
			fwp1[e[i].first][e[i].second] = min(fwp1[e[i].first][e[i].second], c[i]);
		if (!P2[i])
			fwp2[e[i].first][e[i].second] = min(fwp2[e[i].first][e[i].second], c[i]);
	}
	for (int k = 0; k < n; k++) for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) {
		fw[i][j] = min(fw[i][j], fw[i][k] + fw[k][j]);
		fwp1[i][j] = min(fwp1[i][j], fwp1[i][k] + fwp1[k][j]);
		fwp2[i][j] = min(fwp2[i][j], fwp2[i][k] + fwp2[k][j]);
	}

	if (OO) {
		cout << "fw\n";
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n; j++) cout << fw[i][j] << " "; cout << '\n';
		}
		cout << "fwp1\n";
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n; j++) cout << fwp1[i][j] << " "; cout << '\n';
		}
		cout << "fwp2\n";
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n; j++) cout << fwp2[i][j] << " "; cout << '\n';
		}
		cout << "path1:\n";
		for (const auto &i : path1) cout << i << " "; cout << '\n';
		cout << "path2:\n";
		for (const auto &i : path2) cout << i << " "; cout << '\n';
	}

	// costs for path 1
	for (int i = 0; i < m; i++) {
		int u = e[i].first, v = e[i].second;
		if (!P1[i]) {
			if (fw[0][v] == md || fw[u][n - 1] == md) {
				if (fw[0][n - 1] == md)
					cost[i] += inf;
				else
					cost[i] += fw[0][n - 1];
			}
			else if (fw[0][n - 1] == md)
				cost[i] += fw[0][v] + c[i] + fw[u][n - 1];
			else
				cost[i] += min(fw[0][n - 1], fw[0][v] + c[i] + fw[u][n - 1]);
		}
		else {
			int best = md;
			for (int l = 0; l < P1[i]; l++) for (int r = P1[i]; r <= path1.size(); r++) {
				u = e[path1[l]].first, v = e[path1[r - 1]].second;
				if (fw[0][u] != md && fwp1[u][v] != md && fw[v][n - 1] != md)
					best = min(best, fw[0][u] + fwp1[u][v] + fw[v][n - 1]);
			}
			if (best == md)
				cost[i] += inf;
			else
				cost[i] += best;
		}
	}

	// same thing for path 2
	for (int i = 0; i < m; i++) {
		int u = e[i].first, v = e[i].second;
		if (!P2[i]) {
			if (fw[n - 1][v] == md || fw[u][0] == md) {
				if (fw[n - 1][0] == md)
					cost[i] += inf;
				else
					cost[i] += fw[n - 1][0];
			}
			else if (fw[n - 1][0] == md)
				cost[i] += fw[n - 1][v] + c[i] + fw[u][0];
			else
				cost[i] += min(fw[n - 1][0], fw[n - 1][v] + c[i] + fw[u][0]);
		}
		else {
			int best = md;
			for (int l = 0; l < P2[i]; l++) for (int r = P2[i]; r <= path2.size(); r++) {
				u = e[path2[l]].first, v = e[path2[r - 1]].second;
				if (fw[n - 1][u] != md && fwp2[u][v] != md && fw[v][0] != md)
					best = min(best, fw[n - 1][u] + fwp2[u][v] + fw[v][0]);
			}
			if (best == md)
				cost[i] += inf;
			else
				cost[i] += best;
		}
	}

	ll ans = inf;
	if (fw[0][n - 1] != md && fw[n - 1][0] != md)
		ans = min(ans, (ll)fw[0][n - 1] + fw[n - 1][0]);
	for (int i = 0; i < m; i++)
		ans = min(ans, cost[i] + d[i]);
	if (ans > 2 * md)
		cout << "-1\n";
	else
		cout << ans << '\n';
}

Compilation message

ho_t4.cpp: In function 'int main()':
ho_t4.cpp:79:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < path1.size(); i++)
                  ~~^~~~~~~~~~~~~~
ho_t4.cpp:81:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < path2.size(); i++)
                  ~~^~~~~~~~~~~~~~
ho_t4.cpp:106:4: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
    for (int j = 0; j < n; j++) cout << fw[i][j] << " "; cout << '\n';
    ^~~
ho_t4.cpp:106:57: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
    for (int j = 0; j < n; j++) cout << fw[i][j] << " "; cout << '\n';
                                                         ^~~~
ho_t4.cpp:110:4: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
    for (int j = 0; j < n; j++) cout << fwp1[i][j] << " "; cout << '\n';
    ^~~
ho_t4.cpp:110:59: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
    for (int j = 0; j < n; j++) cout << fwp1[i][j] << " "; cout << '\n';
                                                           ^~~~
ho_t4.cpp:114:4: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
    for (int j = 0; j < n; j++) cout << fwp2[i][j] << " "; cout << '\n';
    ^~~
ho_t4.cpp:114:59: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
    for (int j = 0; j < n; j++) cout << fwp2[i][j] << " "; cout << '\n';
                                                           ^~~~
ho_t4.cpp:117:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for (const auto &i : path1) cout << i << " "; cout << '\n';
   ^~~
ho_t4.cpp:117:49: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   for (const auto &i : path1) cout << i << " "; cout << '\n';
                                                 ^~~~
ho_t4.cpp:119:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for (const auto &i : path2) cout << i << " "; cout << '\n';
   ^~~
ho_t4.cpp:119:49: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   for (const auto &i : path2) cout << i << " "; cout << '\n';
                                                 ^~~~
ho_t4.cpp:139:58: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int l = 0; l < P1[i]; l++) for (int r = P1[i]; r <= path1.size(); r++) {
                                                        ~~^~~~~~~~~~~~~~~
ho_t4.cpp:168:58: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int l = 0; l < P2[i]; l++) for (int r = P2[i]; r <= path2.size(); r++) {
                                                        ~~^~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 27 ms 888 KB Output is correct
2 Correct 27 ms 760 KB Output is correct
3 Correct 27 ms 888 KB Output is correct
4 Correct 28 ms 888 KB Output is correct
5 Correct 6 ms 508 KB Output is correct
6 Correct 28 ms 760 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 6 ms 376 KB Output is correct
10 Correct 34 ms 888 KB Output is correct
11 Correct 35 ms 888 KB Output is correct
12 Correct 39 ms 888 KB Output is correct
13 Correct 27 ms 888 KB Output is correct
14 Correct 26 ms 888 KB Output is correct
15 Correct 27 ms 888 KB Output is correct
16 Correct 27 ms 888 KB Output is correct

Subtask #2
11.0 / 11.0

# 결과 실행 시간 메모리 Grader output
1 Correct 62 ms 3552 KB Output is correct
2 Correct 63 ms 3512 KB Output is correct
3 Correct 62 ms 3544 KB Output is correct
4 Correct 27 ms 1016 KB Output is correct
5 Correct 27 ms 892 KB Output is correct
6 Correct 27 ms 888 KB Output is correct
7 Correct 26 ms 888 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 56 ms 3516 KB Output is correct
10 Correct 56 ms 3476 KB Output is correct
11 Correct 57 ms 3500 KB Output is correct
12 Correct 62 ms 3808 KB Output is correct
13 Correct 59 ms 3432 KB Output is correct
14 Correct 60 ms 3588 KB Output is correct

Subtask #3
21.0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 30 ms 888 KB Output is correct
2 Correct 26 ms 760 KB Output is correct
3 Correct 45 ms 2868 KB Output is correct
4 Correct 31 ms 760 KB Output is correct
5 Correct 52 ms 3536 KB Output is correct
6 Correct 4 ms 376 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 49 ms 3512 KB Output is correct
9 Correct 50 ms 3476 KB Output is correct
10 Correct 55 ms 3812 KB Output is correct
11 Correct 50 ms 3424 KB Output is correct
12 Correct 51 ms 3564 KB Output is correct
13 Correct 5 ms 376 KB Output is correct
14 Correct 5 ms 376 KB Output is correct
15 Correct 5 ms 376 KB Output is correct
16 Correct 5 ms 376 KB Output is correct
17 Correct 5 ms 376 KB Output is correct
18 Correct 5 ms 376 KB Output is correct
19 Correct 53 ms 3804 KB Output is correct
20 Correct 57 ms 3496 KB Output is correct
21 Correct 54 ms 3496 KB Output is correct
22 Correct 51 ms 3496 KB Output is correct

Subtask #4
63.0 / 63.0

# 결과 실행 시간 메모리 Grader output
1 Correct 27 ms 888 KB Output is correct
2 Correct 27 ms 760 KB Output is correct
3 Correct 27 ms 888 KB Output is correct
4 Correct 28 ms 888 KB Output is correct
5 Correct 6 ms 508 KB Output is correct
6 Correct 28 ms 760 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 6 ms 376 KB Output is correct
10 Correct 34 ms 888 KB Output is correct
11 Correct 35 ms 888 KB Output is correct
12 Correct 39 ms 888 KB Output is correct
13 Correct 27 ms 888 KB Output is correct
14 Correct 26 ms 888 KB Output is correct
15 Correct 27 ms 888 KB Output is correct
16 Correct 27 ms 888 KB Output is correct
17 Correct 62 ms 3552 KB Output is correct
18 Correct 63 ms 3512 KB Output is correct
19 Correct 62 ms 3544 KB Output is correct
20 Correct 27 ms 1016 KB Output is correct
21 Correct 27 ms 892 KB Output is correct
22 Correct 27 ms 888 KB Output is correct
23 Correct 26 ms 888 KB Output is correct
24 Correct 5 ms 376 KB Output is correct
25 Correct 56 ms 3516 KB Output is correct
26 Correct 56 ms 3476 KB Output is correct
27 Correct 57 ms 3500 KB Output is correct
28 Correct 62 ms 3808 KB Output is correct
29 Correct 59 ms 3432 KB Output is correct
30 Correct 60 ms 3588 KB Output is correct
31 Correct 30 ms 888 KB Output is correct
32 Correct 26 ms 760 KB Output is correct
33 Correct 45 ms 2868 KB Output is correct
34 Correct 31 ms 760 KB Output is correct
35 Correct 52 ms 3536 KB Output is correct
36 Correct 4 ms 376 KB Output is correct
37 Correct 5 ms 376 KB Output is correct
38 Correct 49 ms 3512 KB Output is correct
39 Correct 50 ms 3476 KB Output is correct
40 Correct 55 ms 3812 KB Output is correct
41 Correct 50 ms 3424 KB Output is correct
42 Correct 51 ms 3564 KB Output is correct
43 Correct 5 ms 376 KB Output is correct
44 Correct 5 ms 376 KB Output is correct
45 Correct 5 ms 376 KB Output is correct
46 Correct 5 ms 376 KB Output is correct
47 Correct 5 ms 376 KB Output is correct
48 Correct 5 ms 376 KB Output is correct
49 Correct 53 ms 3804 KB Output is correct
50 Correct 57 ms 3496 KB Output is correct
51 Correct 54 ms 3496 KB Output is correct
52 Correct 51 ms 3496 KB Output is correct
53 Correct 96 ms 3548 KB Output is correct
54 Correct 61 ms 3544 KB Output is correct
55 Correct 61 ms 3544 KB Output is correct
56 Correct 26 ms 888 KB Output is correct
57 Correct 26 ms 888 KB Output is correct
58 Correct 64 ms 2948 KB Output is correct
59 Correct 63 ms 3072 KB Output is correct
60 Correct 63 ms 2824 KB Output is correct
61 Correct 63 ms 2824 KB Output is correct
62 Correct 60 ms 2960 KB Output is correct
63 Correct 63 ms 2836 KB Output is correct
64 Correct 61 ms 3028 KB Output is correct
65 Correct 59 ms 3016 KB Output is correct
66 Correct 59 ms 3032 KB Output is correct
67 Correct 31 ms 3184 KB Output is correct
68 Correct 58 ms 3656 KB Output is correct
69 Correct 55 ms 3456 KB Output is correct
70 Correct 63 ms 3492 KB Output is correct
71 Correct 59 ms 3628 KB Output is correct
72 Correct 61 ms 3508 KB Output is correct
73 Correct 61 ms 3480 KB Output is correct
74 Correct 62 ms 3524 KB Output is correct