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답안 #224116

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
224116 2020-04-17T08:12:52 Z oolimry Olympic Bus (JOI20_ho_t4) C++14
16 / 100
 102 ms 4840 KB 
#include <bits/stdc++.h>

using namespace std;
long long inf = (1LL << 56LL);

typedef pair<long long, long long> ii;
vector<ii> adj[205];
vector<ii> adjR[205];
long long dis[205];
long long dis1[205];
long long disn[205];
long long dis1R[205];
long long disnR[205];

int n, m; 

long long dij(int s, int t){
	fill(dis, dis + (n+3), inf);
	
	priority_queue<ii, vector<ii>, greater<ii> > dtr; /// use greater<int>
	dtr.push(ii(0,s));
    dis[s] = 0;
    ///first is minpath, second is vertex
    while(!dtr.empty()){
        ii cur = dtr.top();
        dtr.pop();
        for(int j = 0;j < adj[cur.second].size();j++){
            ii nei = adj[cur.second][j];
            if(nei.first + cur.first < dis[nei.second]){
                dis[nei.second] = nei.first + cur.first;
                dtr.push(ii(dis[nei.second],nei.second));
            }
        }
    }
    return dis[t];
}

long long dijR(int s, int t){
	fill(dis, dis + (n+3), inf);
	
	priority_queue<ii, vector<ii>, greater<ii> > dtr; /// use greater<int>
	dtr.push(ii(0,s));
    dis[s] = 0;
    ///first is minpath, second is vertex
    while(!dtr.empty()){
        ii cur = dtr.top();
        dtr.pop();
        for(int j = 0;j < adjR[cur.second].size();j++){
            ii nei = adjR[cur.second][j];
            if(nei.first + cur.first < dis[nei.second]){
                dis[nei.second] = nei.first + cur.first;
                dtr.push(ii(dis[nei.second],nei.second));
            }
        }
    }
    return dis[t];
}

struct edge{
	long long u; long long v; long long c; long long d;
};
vector<edge> edges;

void prin(long long ans){
	if(ans >= inf) ans = -1;
	cout << ans;
	exit(0);
}

void subtask1(){
	long long ans = dij(1, n)+ dij(n, 1);
	for(int i = 0;i < m;i++){
		for(int i = 1;i <= n;i++) adj[i].clear();
		
		long long res = 0;
		for(int j = 0;j < m;j++){
			edge e = edges[j];
			if(i == j){
				adj[e.v].push_back(ii(e.c,e.u));
				res += e.d;
			}
			else adj[e.u].push_back(ii(e.c,e.v));
		}
		//cout << dij(1,n) + dij(n,1) + res << "\n";
		ans = min(ans, dij(1,n) + dij(n,1) + res);
	}
	
	prin(ans);
}

int main(){
	//freopen("i.txt","r",stdin);
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	
	cin >> n >> m;
	for(int i = 0;i < m;i++){
		long long u, v, c, d; cin >> u >> v >> c >> d;
		edges.push_back({u,v,c,d});
		adj[u].push_back(ii(c,v));
		adjR[v].push_back(ii(c,u));
	}
	
	if(m <= 1000) subtask1();
	
	dij(1,n);
	for(int i = 1;i <= n;i++) dis1[i] = dis[i];
	
	dij(n,1);
	for(int i = 1;i <= n;i++) disn[i] = dis[i];
	
	dijR(1,n);
	for(int i = 1;i <= n;i++) dis1R[i] = dis[i];
	
	dijR(n,1);
	for(int i = 1;i <= n;i++) disnR[i] = dis[i];
	
	long long ans = dis1[n] + disn[1];
	for(edge e : edges){
		///edge goes v -> u
		ans = min(ans, e.d + dis1[n] + disn[e.v] + dis1R[e.u] + e.c);
		ans = min(ans, e.d + disn[1] + dis1[e.v] + disnR[e.u] + e.c);
		ans = min(ans, e.d + dis1[e.v] + disnR[e.u] + disn[e.v] + dis1R[e.u] + 2 * e.c);
	}
	
	prin(ans);
}

Compilation message

ho_t4.cpp: In function 'long long int dij(int, int)':
ho_t4.cpp:27:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j = 0;j < adj[cur.second].size();j++){
                       ~~^~~~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp: In function 'long long int dijR(int, int)':
ho_t4.cpp:48:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j = 0;j < adjR[cur.second].size();j++){
                       ~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 48 ms 512 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 68 ms 384 KB Output is correct
4 Correct 72 ms 384 KB Output is correct
5 Correct 36 ms 512 KB Output is correct
6 Correct 6 ms 384 KB Output is correct
7 Correct 4 ms 384 KB Output is correct
8 Correct 4 ms 384 KB Output is correct
9 Correct 19 ms 384 KB Output is correct
10 Correct 101 ms 384 KB Output is correct
11 Correct 102 ms 384 KB Output is correct
12 Correct 99 ms 504 KB Output is correct
13 Correct 41 ms 384 KB Output is correct
14 Correct 54 ms 384 KB Output is correct
15 Correct 50 ms 384 KB Output is correct
16 Correct 51 ms 512 KB Output is correct

Subtask #2
11.0 / 11.0

# 결과 실행 시간 메모리 Grader output
1 Correct 30 ms 4444 KB Output is correct
2 Correct 30 ms 4592 KB Output is correct
3 Correct 31 ms 4592 KB Output is correct
4 Correct 6 ms 512 KB Output is correct
5 Correct 46 ms 384 KB Output is correct
6 Correct 9 ms 384 KB Output is correct
7 Correct 7 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 29 ms 4464 KB Output is correct
10 Correct 33 ms 4584 KB Output is correct
11 Correct 31 ms 4592 KB Output is correct
12 Correct 31 ms 4456 KB Output is correct
13 Correct 32 ms 4456 KB Output is correct
14 Correct 33 ms 4840 KB Output is correct

Subtask #3
0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 49 ms 384 KB Output is correct
2 Correct 7 ms 384 KB Output is correct
3 Correct 23 ms 4240 KB Output is correct
4 Correct 6 ms 384 KB Output is correct
5 Correct 26 ms 4464 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 31 ms 4464 KB Output is correct
9 Correct 30 ms 4452 KB Output is correct
10 Incorrect 27 ms 4456 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# 결과 실행 시간 메모리 Grader output
1 Correct 48 ms 512 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 68 ms 384 KB Output is correct
4 Correct 72 ms 384 KB Output is correct
5 Correct 36 ms 512 KB Output is correct
6 Correct 6 ms 384 KB Output is correct
7 Correct 4 ms 384 KB Output is correct
8 Correct 4 ms 384 KB Output is correct
9 Correct 19 ms 384 KB Output is correct
10 Correct 101 ms 384 KB Output is correct
11 Correct 102 ms 384 KB Output is correct
12 Correct 99 ms 504 KB Output is correct
13 Correct 41 ms 384 KB Output is correct
14 Correct 54 ms 384 KB Output is correct
15 Correct 50 ms 384 KB Output is correct
16 Correct 51 ms 512 KB Output is correct
17 Correct 30 ms 4444 KB Output is correct
18 Correct 30 ms 4592 KB Output is correct
19 Correct 31 ms 4592 KB Output is correct
20 Correct 6 ms 512 KB Output is correct
21 Correct 46 ms 384 KB Output is correct
22 Correct 9 ms 384 KB Output is correct
23 Correct 7 ms 384 KB Output is correct
24 Correct 5 ms 384 KB Output is correct
25 Correct 29 ms 4464 KB Output is correct
26 Correct 33 ms 4584 KB Output is correct
27 Correct 31 ms 4592 KB Output is correct
28 Correct 31 ms 4456 KB Output is correct
29 Correct 32 ms 4456 KB Output is correct
30 Correct 33 ms 4840 KB Output is correct
31 Correct 49 ms 384 KB Output is correct
32 Correct 7 ms 384 KB Output is correct
33 Correct 23 ms 4240 KB Output is correct
34 Correct 6 ms 384 KB Output is correct
35 Correct 26 ms 4464 KB Output is correct
36 Correct 5 ms 384 KB Output is correct
37 Correct 5 ms 384 KB Output is correct
38 Correct 31 ms 4464 KB Output is correct
39 Correct 30 ms 4452 KB Output is correct
40 Incorrect 27 ms 4456 KB Output isn't correct
41 Halted 0 ms 0 KB -