Submission #769355

#	Time	Username	Problem	Language	Result	Execution time	Memory
769355		Alora	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	217 ms	24264 KiB

commuter_pass

#include <bits/stdc++.h>
#define name "cownav"
#define fi(i,a,b) for(int i = a; i <= b; i++)
#define fid(i,a,b) for(int i = a; i >= b; i--)
#define ll long long
#define f first
#define se second
#define pii pair<ll, int>
#define getbit(i, j) ((i >> j) & 1)
#define pb push_back
#define all(v) v.begin(), v.end()
#define maxn 200005
const int M = 1e9 + 7;
using namespace std;
int n, m, S, T, U, V, xd[2*maxn];
struct dl{int f, se, id;};
vector <dl> g[maxn];
ll L[maxn];

void dij(){
    fi(i, 1, n) L[i] = 1e18;
    L[S] = 0;
    priority_queue <pii> q;
    q.push({0, S});
    while(q.size()){
        ll h = -q.top().f;
        int u = q.top().se;
        q.pop();
        if(h != L[u]) continue;
        for(auto e: g[u]){
            int v = e.f, w = e.se;
            if(L[v] > L[u] + w){
                L[v] = L[u] + w;
                q.push({-L[v], v});
            }
        }
    }
}
void dfs(int u){
    for(auto e: g[u]){
        int v = e.f, w = e.se, id = e.id;
        if(xd[id]) continue;
        xd[id] = 1;
        if(L[v] + w == L[u]) xd[id] = 2;
        dfs(v);
    }
}

void dij1(){
    fi(i, 1, n) L[i] = 1e18;
    L[U] = 0;
    priority_queue <pii> q;
    q.push({0, U});
    while(q.size()){
        ll h = -q.top().f;
        int u = q.top().se;
        q.pop();
        if(h != L[u]) continue;
        for(auto e: g[u]){
            int v = e.f, w = e.se, id = e.id;
            if(xd[id] == 2) w = 0;
            if(L[v] > L[u] + w){
                L[v] = L[u] + w;
                q.push({-L[v], v});
            }

        }
    }
}

signed main(){
	ios_base::sync_with_stdio(0);
	cin.tie(NULL);
 //   freopen(name".in", "r", stdin);
   // freopen(name".out", "w", stdout);
    cin >> n >> m;
    cin >> S >> T >> U >> V;
    fi(i, 1, m){
        int u, v, z; cin >> u >> v >> z;
        g[u].pb({v, z, i});
        g[v].pb({u, z, i});
    }
    dij();
    dfs(T);
   // fi(i, 1, m) cout << xd[i] << " "; cout << endl;
    dij1();
    cout << L[V];
}

• Subtask 1: 0 / 16
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45