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답안 #237268

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
237268 2020-06-05T15:21:30 Z AMO5 Olympic Bus (JOI20_ho_t4) C++
5 / 100
 1000 ms 3828 KB 
#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define eb emplace_back
#define mt make_tuple
#define all(x) (x).begin(), (x).end() 
#define MOD 1000000007

typedef long long ll;
typedef pair <int, int> ii;
typedef pair <ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef long double ld;

const ll INF=LLONG_MAX;
const int mxn=202;
ll dist1[mxn],dist2[mxn],d[50005];
vector<pair<int,ll>>adj[mxn];
int n;

struct flag{
	int u,v; ll c;
	flag(int u, int v, ll c):u(u),v(v),c(c){}
};

vector<flag>str;
//subtask 1
ll dij(int ind){ 
	//set all dist = INF
	for(int i=0; i<n; i++)
		dist1[i]=dist2[i]=ll(1e18);
	
	priority_queue<pair<ll,int>,vector<pair<ll,int>>,greater<pair<ll,int>>>pq;
	//from 1 to n;
	dist1[0]=0LL;
	pq.push({dist1[0],0});
	while(!pq.empty()){
		auto tp = pq.top();
		pq.pop();
		int u = tp.se;
		if(u==n-1)break;
		if(u==str[ind].v){
			int v = str[ind].u;
			ll w = str[ind].c;
			if(dist1[v]>dist1[u]+w){
				dist1[v] = dist1[u]+w;
				pq.push({dist1[v],v});
			}
		}
		for(auto x:adj[u]){
			int v = x.fi;
			ll w = x.se;
			if(str[ind].u==u&&str[ind].v==v&&str[ind].c==w)continue;
			if(dist1[v]>dist1[u]+w){
				dist1[v] = dist1[u]+w;
				pq.push({dist1[v],v});
			}
		}
	}
	//from n to 1;
	dist2[n-1]=0LL;
	pq.push({dist2[n-1],n-1});
	while(!pq.empty()){
		auto tp = pq.top();
		pq.pop();
		int u = tp.se;
		if(u==0)break;
		if(u==str[ind].v){
			int v = str[ind].u;
			ll w = str[ind].c;
			if(dist2[v]>dist2[u]+w){
				dist2[v] = dist2[u]+w;
				pq.push({dist2[v],v});
			}
		}
		for(auto x:adj[u]){
			int v = x.fi;
			ll w = x.se;
			if(str[ind].u==u&&str[ind].v==v&&str[ind].c==w)continue;
			if(dist2[v]>dist2[u]+w){
				dist2[v] = dist2[u]+w;
				pq.push({dist2[v],v});
			}
		}
	}
	if(dist1[n-1]==1e18||dist2[0]==1e18)return 2e18;
	return dist1[n-1]+dist2[0];
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    //freopen("input.txt","r",stdin); freopen("output.txt","w",stdout);
	int m; 
	cin >> n >> m;
	str.eb(-1,-1,0);
	d[0]=0LL;
	for(int i=1; i<=m; i++){
		int u,v; ll c;
		cin >> u >> v >> c >> d[i];
		u--; v--;
		adj[u].eb(v,c);
		str.eb(u,v,c);
	}
	ll ans = (ll)2e18;
	for(int i=0; i<=m; i++){
		ll now = dij(i);
		ans = min(ans, now+d[i]);
	}
	if(ans==2e18)ans = -1;
	cout << ans << endl;
}
	
// READ & UNDERSTAND
// ll, int overflow, array bounds, memset(0)
// special cases (n=1?), n+1 (1-index)
// do smth instead of nothing & stay organized
// WRITE STUFF DOWN

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 32 ms 384 KB Output is correct
2 Correct 5 ms 512 KB Output is correct
3 Correct 34 ms 384 KB Output is correct
4 Correct 42 ms 384 KB Output is correct
5 Correct 16 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 7 ms 512 KB Output is correct
10 Correct 83 ms 384 KB Output is correct
11 Correct 79 ms 384 KB Output is correct
12 Correct 82 ms 384 KB Output is correct
13 Correct 29 ms 384 KB Output is correct
14 Correct 38 ms 512 KB Output is correct
15 Correct 25 ms 384 KB Output is correct
16 Correct 39 ms 384 KB Output is correct

Subtask #2
0 / 11.0

# 결과 실행 시간 메모리 Grader output
1 Execution timed out 1069 ms 3828 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 35 ms 384 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Execution timed out 1084 ms 3192 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# 결과 실행 시간 메모리 Grader output
1 Correct 32 ms 384 KB Output is correct
2 Correct 5 ms 512 KB Output is correct
3 Correct 34 ms 384 KB Output is correct
4 Correct 42 ms 384 KB Output is correct
5 Correct 16 ms 384 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 7 ms 512 KB Output is correct
10 Correct 83 ms 384 KB Output is correct
11 Correct 79 ms 384 KB Output is correct
12 Correct 82 ms 384 KB Output is correct
13 Correct 29 ms 384 KB Output is correct
14 Correct 38 ms 512 KB Output is correct
15 Correct 25 ms 384 KB Output is correct
16 Correct 39 ms 384 KB Output is correct
17 Execution timed out 1069 ms 3828 KB Time limit exceeded
18 Halted 0 ms 0 KB -