oj.uz

Submission #237270

# Submission time Handle Problem Language Result Execution time Memory
237270 2020-06-05T15:34:57 Z AMO5 Olympic Bus (JOI20_ho_t4) C++
5 / 100
 1000 ms 2932 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 1,2
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);
		if(m>1000)d[i]=min(d[i],d[i+1]);
		ans = min(ans, now+d[i]);
		if(m>1000)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

# Verdict Execution time Memory Grader output
1 Correct 36 ms 384 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 33 ms 384 KB Output is correct
4 Correct 44 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 384 KB Output is correct
10 Correct 87 ms 384 KB Output is correct
11 Correct 81 ms 384 KB Output is correct
12 Correct 84 ms 384 KB Output is correct
13 Correct 31 ms 384 KB Output is correct
14 Correct 41 ms 384 KB Output is correct
15 Correct 26 ms 384 KB Output is correct
16 Correct 40 ms 384 KB Output is correct

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1097 ms 2932 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 384 KB Output is correct
2 Correct 6 ms 384 KB Output is correct
3 Execution timed out 1086 ms 2552 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 36 ms 384 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 33 ms 384 KB Output is correct
4 Correct 44 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 384 KB Output is correct
10 Correct 87 ms 384 KB Output is correct
11 Correct 81 ms 384 KB Output is correct
12 Correct 84 ms 384 KB Output is correct
13 Correct 31 ms 384 KB Output is correct
14 Correct 41 ms 384 KB Output is correct
15 Correct 26 ms 384 KB Output is correct
16 Correct 40 ms 384 KB Output is correct
17 Execution timed out 1097 ms 2932 KB Time limit exceeded
18 Halted 0 ms 0 KB -