Submission #362104

#TimeUsernameProblemLanguageResultExecution timeMemory
362104AmineWeslatiCommuter Pass (JOI18_commuter_pass)C++14
100 / 100
517 ms51984 KiB
//Never stop trying
#include "bits/stdc++.h"
using namespace std;
#define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)

typedef long long ll;
#define int ll
typedef string str;
typedef long double ld;
typedef pair<int, int> pi;
#define fi first
#define se second
typedef vector<int> vi;
typedef vector<pi> vpi;
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define endl "\n"
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)

const int MOD = 1e9 + 7; //998244353
const ll INF = 1e18;
const int MX = 2e5 + 10;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; //right left down up


template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); } // divide a by b rounded up
//constexpr int log2(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
//mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
ll random(ll a, ll b){
    return a + rng() % (b - a + 1);
}
#ifndef LOCAL  
#define cerr if(false) cerr
#endif
#define dbg(x) cerr << #x << " : " << x << endl; 
#define dbgs(x,y) cerr << #x << " : " << x << " / " << #y << " : " << y << endl;
#define dbgv(v) cerr << #v << " : " << "[ "; for(auto it : v) cerr << it << ' '; cerr << ']' << endl;
#define here() cerr << "here" << endl;

void IO() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin); 
    freopen("output.txt", "w", stdout);
#endif
}
/////////////////////////ONLY CLEAN CODES ALLOWED/////////////////////////


int N,M,S,T,U,V;
vpi adj[MX],adj2[MX];
vector<pair<pi,int>>vec; //edges
vi dist,CS(MX),CT(MX);

void sp(vpi adj[], int u){
	dist.assign(N+1,INF); dist[u]=0;

	priority_queue<pi,vpi,greater<pi>>q; q.push({0,u});

	while(sz(q)){
		int u=q.top().se,d=q.top().fi;
		q.pop();
		if(d>dist[u]) continue;

		for(auto v: adj[u]) if(dist[v.fi]>d+v.se){
			dist[v.fi]=d+v.se;
			q.push({dist[v.fi],v.fi});
		}
	}

}

int32_t main() {
    boost; IO();

    cin>>N>>M>>S>>T>>U>>V;
    FOR(i,0,M){
    	int u,v,w; cin>>u>>v>>w;
    	vec.pb({{u,v},w});
    	adj[u].pb({v,w});
    	adj[v].pb({u,w});
    }

    if(N<=300){
    	int g[N+1][N+1];
    	FOR(i,1,N+1) FOR(j,1,N+1) g[i][j]=INF;
    	FOR(i,1,N+1) g[i][i]=0;

    	for(auto x: vec){
    		int u=x.fi.fi,v=x.fi.se,w=x.se;
    		g[u][v]=g[v][u]=w;
    	}

    	FOR(k,1,N+1) FOR(i,1,N+1) FOR(j,1,N+1) 
    		ckmin(g[i][j],g[i][k]+g[k][j]);

    	int ans=g[U][V];
		FOR(u,1,N+1) FOR(v,1,N+1){
			if(g[S][u]+g[u][v]+g[v][T]==g[S][T]){
				ckmin(ans,g[U][u]+g[v][V]);
				ckmin(ans,g[V][u]+g[v][U]);
			}

		}
		cout << ans << endl;

    }
    else{
	    sp(adj,S);
	    FOR(i,1,N+1) CS[i]=dist[i];
	    sp(adj,T);
	    FOR(i,1,N+1) CT[i]=dist[i];


	    for(auto x: vec){
	    	int u=x.fi.fi,v=x.fi.se,w=x.se;
	    	adj2[u].pb({v,w});
	    	adj2[v].pb({u,w});

	    	if(CS[u]+w+CT[v]==CS[T]) adj2[u].eb(v,0);
	    	if(CS[v]+w+CT[u]==CS[T]) adj2[v].eb(u,0);
	    }
	    sp(adj2,U);
	    int ans=dist[V];

		
		FOR(i,1,N+1) adj2[i].clear();
		for(auto x: vec){
	    	int u=x.fi.fi,v=x.fi.se,w=x.se;
	    	adj2[u].pb({v,w});
	    	adj2[v].pb({u,w});

	    	if(CS[u]+w+CT[v]==CS[T]) adj2[v].eb(u,0);
	    	if(CS[v]+w+CT[u]==CS[T]) adj2[u].eb(v,0);
	    }
	    sp(adj2,U);
	    ckmin(ans,dist[V]);


	    cout << ans << endl;
    }

    

    return 0;
}
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