oj.uz

답안 #201029

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
201029 2020-02-09T06:26:41 Z gs14004 Olympic Bus (JOI20_ho_t4) C++17
100 / 100
 558 ms 4376 KB 
#include <bits/stdc++.h>
#define sz(v) ((int)(v).size())
#define all(v) (v).begin(), (v).end()
using namespace std;
using lint = long long;
using pi = pair<lint, lint>;
const int MAXN = 205;

int n, m;
lint adj[MAXN][MAXN];
int trk[MAXN][MAXN];
lint dap[50005];

struct edg{
	int u, v, c, d, idx;
}ed[50005];

vector<int> pth;

void dfs(int x, int y){
	if(trk[x][y] <= 0) pth.push_back(-trk[x][y]);
	else{
		dfs(x, trk[x][y]);
		dfs(trk[x][y], y);
	}
}

bool chk[50005];
lint kek[MAXN][MAXN];

lint Do_rev(int i, int s, int t){
	memset(kek, 0x3f, sizeof(kek));
	for(int j=0; j<m; j++){
		int u = ed[j].u;
		int v = ed[j].v;
		lint c = ed[j].c;
		if(j != i) kek[u][v] = min(kek[u][v], c);
		else kek[v][u] = min(kek[v][u], c);
	}
	lint dist[MAXN];
	bool vis[MAXN] = {};
	memset(dist, 0x3f, sizeof(dist));
	dist[s] = 0;
	for(int i=0; i<n; i++){
		lint cur = 1e18;
		int pos = -1;
		for(int j=1; j<=n; j++){
			if(!vis[j] && dist[j] < cur){
				cur = dist[j];
				pos = j;
			}
		}
		if(pos == -1) break;
		vis[pos] = 1;
		for(int j=1; j<=n; j++){
			dist[j] = min(dist[pos] + kek[pos][j], dist[j]);
		}
	}
	return dist[t];
}

pi dist[2][MAXN][2]; // distance, which edge

void dijk(int s, int flag){
	bool vis[MAXN] = {};
	vector<edg> gph[MAXN];
	for(int i=0; i<m; i++){
		gph[ed[i].u].push_back(ed[i]);
	}
	dist[flag][s][0] = pi(0, 0);
	for(int i=0; i<n; i++){
		lint cur = 1e18;
		int pos = -1;
		for(int j=1; j<=n; j++){
			if(!vis[j] && dist[flag][j][0].first < cur){
				cur = dist[flag][j][0].first;
				pos = j;
			}
		}
		if(pos == -1) break;
		vis[pos] = 1;
		for(auto &j : gph[pos]){
			if(dist[flag][j.v][0].first > dist[flag][pos][0].first + j.c){
				dist[flag][j.v][0].first = dist[flag][pos][0].first + j.c;
				dist[flag][j.v][0].second = j.idx;
			}
		}
	}
	for(int i=1; i<=n; i++){
		if(s == i){
			dist[flag][i][1].first = 0;
			continue;
		}
		dist[flag][i][1].first = Do_rev(dist[flag][i][0].second, s, i);
	}
}

void solve(int s, int t){
	memset(chk, 0, sizeof(chk));
	for(int i=0; i<2; i++){
		for(int j=0; j<MAXN; j++){
			for(int k=0; k<2; k++){
				dist[i][j][k] = pi(1e18, -1);
			}
		}
	}
	pth.clear();
	if(adj[s][t] < 1e17){
		dfs(s, t);
		for(int i=0; i<sz(pth); i++){
			chk[pth[i]] = 1;
		}
	}
	dijk(s, 0);
	for(int i=0; i<m; i++) swap(ed[i].u, ed[i].v);
	dijk(t, 1);
	for(int i=0; i<m; i++) swap(ed[i].u, ed[i].v);
	for(int i=0; i<m; i++){
		if(!chk[i]){
			lint foo = ed[i].c;
			if(dist[0][ed[i].v][0].second == i) foo += dist[0][ed[i].v][1].first;
			else foo += dist[0][ed[i].v][0].first;
			if(dist[1][ed[i].v][0].second == i) foo += dist[1][ed[i].u][1].first;
			else foo += dist[1][ed[i].u][0].first;
			dap[i] += min(adj[s][t], foo);
		}
		else{
			dap[i] += Do_rev(i, s, t);
		}
	}
}

int main(){
	scanf("%d %d",&n,&m);
	memset(adj, 0x1f, sizeof(adj));
	for(int i=1; i<=n; i++) adj[i][i] = 0;
	for(int i=0; i<m; i++){
		scanf("%d %d %d %d",&ed[i].u,&ed[i].v,&ed[i].c,&ed[i].d);
		ed[i].idx = i;
		if(adj[ed[i].u][ed[i].v] > ed[i].c){
			adj[ed[i].u][ed[i].v] = ed[i].c;
			trk[ed[i].u][ed[i].v] = -i;
		}
		dap[i] = ed[i].d;
	}
	for(int i=1; i<=n; i++){
		for(int j=1; j<=n; j++){
			for(int k=1; k<=n; k++){
				if(adj[j][k] > adj[j][i] + adj[i][k]){
					adj[j][k] = adj[j][i] + adj[i][k];
					trk[j][k] = i;
				}
			}
		}
	}
	lint ans = adj[1][n] + adj[n][1];
	solve(1, n);
	solve(n, 1);
	ans = min(ans, *min_element(dap, dap + m));
	if(ans > 1e15) ans = -1;
	cout << ans << endl;
}

Compilation message

ho_t4.cpp: In function 'int main()':
ho_t4.cpp:134:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&m);
  ~~~~~^~~~~~~~~~~~~~~
ho_t4.cpp:138:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d %d %d",&ed[i].u,&ed[i].v,&ed[i].c,&ed[i].d);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 123 ms 1276 KB Output is correct
2 Correct 34 ms 1272 KB Output is correct
3 Correct 151 ms 1324 KB Output is correct
4 Correct 148 ms 1316 KB Output is correct
5 Correct 9 ms 1148 KB Output is correct
6 Correct 54 ms 1264 KB Output is correct
7 Correct 7 ms 1016 KB Output is correct
8 Correct 5 ms 1016 KB Output is correct
9 Correct 6 ms 1196 KB Output is correct
10 Correct 215 ms 1320 KB Output is correct
11 Correct 208 ms 1272 KB Output is correct
12 Correct 212 ms 1324 KB Output is correct
13 Correct 85 ms 1324 KB Output is correct
14 Correct 114 ms 1320 KB Output is correct
15 Correct 118 ms 1400 KB Output is correct
16 Correct 111 ms 1320 KB Output is correct

Subtask #2
11.0 / 11.0

# 결과 실행 시간 메모리 Grader output
1 Correct 454 ms 4324 KB Output is correct
2 Correct 404 ms 4352 KB Output is correct
3 Correct 452 ms 4312 KB Output is correct
4 Correct 147 ms 1272 KB Output is correct
5 Correct 128 ms 1196 KB Output is correct
6 Correct 62 ms 1272 KB Output is correct
7 Correct 28 ms 1272 KB Output is correct
8 Correct 6 ms 1016 KB Output is correct
9 Correct 376 ms 4244 KB Output is correct
10 Correct 358 ms 4168 KB Output is correct
11 Correct 409 ms 4232 KB Output is correct
12 Correct 407 ms 4192 KB Output is correct
13 Correct 406 ms 4204 KB Output is correct
14 Correct 415 ms 4320 KB Output is correct

Subtask #3
21.0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 113 ms 1272 KB Output is correct
2 Correct 61 ms 1144 KB Output is correct
3 Correct 345 ms 3416 KB Output is correct
4 Correct 51 ms 1144 KB Output is correct
5 Correct 380 ms 4232 KB Output is correct
6 Correct 5 ms 1016 KB Output is correct
7 Correct 5 ms 1016 KB Output is correct
8 Correct 305 ms 4208 KB Output is correct
9 Correct 357 ms 4316 KB Output is correct
10 Correct 389 ms 4188 KB Output is correct
11 Correct 381 ms 4156 KB Output is correct
12 Correct 384 ms 4284 KB Output is correct
13 Correct 5 ms 1016 KB Output is correct
14 Correct 5 ms 1016 KB Output is correct
15 Correct 6 ms 1016 KB Output is correct
16 Correct 6 ms 1016 KB Output is correct
17 Correct 6 ms 1016 KB Output is correct
18 Correct 5 ms 1016 KB Output is correct
19 Correct 378 ms 4328 KB Output is correct
20 Correct 384 ms 4220 KB Output is correct
21 Correct 378 ms 4184 KB Output is correct
22 Correct 377 ms 4148 KB Output is correct

Subtask #4
63.0 / 63.0

# 결과 실행 시간 메모리 Grader output
1 Correct 123 ms 1276 KB Output is correct
2 Correct 34 ms 1272 KB Output is correct
3 Correct 151 ms 1324 KB Output is correct
4 Correct 148 ms 1316 KB Output is correct
5 Correct 9 ms 1148 KB Output is correct
6 Correct 54 ms 1264 KB Output is correct
7 Correct 7 ms 1016 KB Output is correct
8 Correct 5 ms 1016 KB Output is correct
9 Correct 6 ms 1196 KB Output is correct
10 Correct 215 ms 1320 KB Output is correct
11 Correct 208 ms 1272 KB Output is correct
12 Correct 212 ms 1324 KB Output is correct
13 Correct 85 ms 1324 KB Output is correct
14 Correct 114 ms 1320 KB Output is correct
15 Correct 118 ms 1400 KB Output is correct
16 Correct 111 ms 1320 KB Output is correct
17 Correct 454 ms 4324 KB Output is correct
18 Correct 404 ms 4352 KB Output is correct
19 Correct 452 ms 4312 KB Output is correct
20 Correct 147 ms 1272 KB Output is correct
21 Correct 128 ms 1196 KB Output is correct
22 Correct 62 ms 1272 KB Output is correct
23 Correct 28 ms 1272 KB Output is correct
24 Correct 6 ms 1016 KB Output is correct
25 Correct 376 ms 4244 KB Output is correct
26 Correct 358 ms 4168 KB Output is correct
27 Correct 409 ms 4232 KB Output is correct
28 Correct 407 ms 4192 KB Output is correct
29 Correct 406 ms 4204 KB Output is correct
30 Correct 415 ms 4320 KB Output is correct
31 Correct 113 ms 1272 KB Output is correct
32 Correct 61 ms 1144 KB Output is correct
33 Correct 345 ms 3416 KB Output is correct
34 Correct 51 ms 1144 KB Output is correct
35 Correct 380 ms 4232 KB Output is correct
36 Correct 5 ms 1016 KB Output is correct
37 Correct 5 ms 1016 KB Output is correct
38 Correct 305 ms 4208 KB Output is correct
39 Correct 357 ms 4316 KB Output is correct
40 Correct 389 ms 4188 KB Output is correct
41 Correct 381 ms 4156 KB Output is correct
42 Correct 384 ms 4284 KB Output is correct
43 Correct 5 ms 1016 KB Output is correct
44 Correct 5 ms 1016 KB Output is correct
45 Correct 6 ms 1016 KB Output is correct
46 Correct 6 ms 1016 KB Output is correct
47 Correct 6 ms 1016 KB Output is correct
48 Correct 5 ms 1016 KB Output is correct
49 Correct 378 ms 4328 KB Output is correct
50 Correct 384 ms 4220 KB Output is correct
51 Correct 378 ms 4184 KB Output is correct
52 Correct 377 ms 4148 KB Output is correct
53 Correct 432 ms 4044 KB Output is correct
54 Correct 449 ms 4180 KB Output is correct
55 Correct 433 ms 4192 KB Output is correct
56 Correct 147 ms 1276 KB Output is correct
57 Correct 149 ms 1400 KB Output is correct
58 Correct 532 ms 3452 KB Output is correct
59 Correct 558 ms 3476 KB Output is correct
60 Correct 529 ms 3584 KB Output is correct
61 Correct 502 ms 3516 KB Output is correct
62 Correct 536 ms 3564 KB Output is correct
63 Correct 535 ms 3504 KB Output is correct
64 Correct 536 ms 3620 KB Output is correct
65 Correct 529 ms 3704 KB Output is correct
66 Correct 514 ms 3576 KB Output is correct
67 Correct 32 ms 4248 KB Output is correct
68 Correct 372 ms 4128 KB Output is correct
69 Correct 366 ms 4192 KB Output is correct
70 Correct 415 ms 4184 KB Output is correct
71 Correct 406 ms 4252 KB Output is correct
72 Correct 402 ms 4300 KB Output is correct
73 Correct 438 ms 4376 KB Output is correct
74 Correct 420 ms 4216 KB Output is correct