Submission #722345

#	Time	Username	Problem	Language	Result	Execution time	Memory
722345		Zflop	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	638 ms	36500 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
 
/*
ID: 10002181
LANG: C++
TASK: lamps
*/
 
using str = string; // yay python!
using ld = long double; // or double, if TL is tight
using ll = long long;
using int64 = ll;
using db = double;
using ull = unsigned long long;
#define int ll
 
#define ch() getchar()
#define pc(x) putchar(x)
#define tcT template<class T
#define tcTU tcT, class U
tcT> using V = vector<T>;
tcT, size_t SZ> using AR = array<T,SZ>;
using vi = V<int>;
using vb = V<bool>;
using vpi = V<pair<int,int>>;
using vvi = V<vi>;
using vl = V<ll>;
using vd = V<ld>;
using vstr = V<str>;
 
#define all(x) begin(x), end(x)
#define sor(x) sort(all(x))
#define rev(x) reverse(all(x))
#define sz(x) (int)(x).size()
#define rall(x) x.rbegin(), x.rend()
#define AR array
 
// loops
#define F0R(i, a, b) for (int i=a; i<b;++i)
#define FOR(i, a) for (int i=0; i<a;++i)
#define FORn(i, a) for (int i=1; i<=a;++i)
#define ROF(i,a) for(int i=a-1; i >= 0;--i)
#define R0F(i,a,b) for(int i=a; i > b;--i)
#define ROFn(i,a) for(int i=a; i > 0;--i)
#define rep(a) F0R(_, a)
#define trav(i,x) for(auto& i:x)
 
// pairs
#define mp make_pair
#define pi pair <int, int>
#define f first
#define s second
 
// vectors
#define lb lower_bound
#define ub upper_bound
#define SUM(v) accumulate(all(v), 0LL)
#define MN(v) *min_element(all(v))
#define MX(v) *max_element(all(v))
#define UNIQUE(a) (a).erase(unique((a).begin(),(a).end()),(a).end())
#define eb emplace_back
#define ft front()
#define bk back()
#define ins insert
#define pf push_front
#define pb push_back
#define emt empty()
#define rsz resize
 
#define pob pop_back()
#define pof pop_front()
 
#define swp(a,b) a^=b^=a^=b
 
#define ts to_string
 
#define setIO()  ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
 
ll MOD = 1e9+7;
const ll MAX = 100000000000;
const ll INF = 1e18; // not too close to LLONG_MAX
const ld PI = acos((ld)-1);
 
#ifdef _DEBUG
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
 
const int dx[4] = {1,0,-1,0}, dy[4] = {0,1,0,-1}; // for every grid problem!!
 
tcT> bool ckmin(T& a, const T& b) {
	return b < a ? a = b, 1 : 0; } // set a = min(a,b)
tcT> bool ckmax(T& a, const T& b) {
	return a < b ? a = b, 1 : 0; }
 
tcTU> T fstTrue(T lo, T hi, U f) {
	hi ++; assert(lo <= hi); // assuming f is increasing
	while (lo < hi) { // find first index such that f is true
		T mid = lo+(hi-lo)/2;
		f(mid) ? hi = mid : lo = mid+1;
	}
	return lo;
}
tcTU> T lstTrue(T lo, T hi, U f) {
	lo --; assert(lo <= hi); // assuming f is decreasing
	while (lo < hi) { // find first index such that f is true
		T mid = lo+(hi-lo+1)/2;
		f(mid) ? lo = mid : hi = mid-1;
	}
	return lo;
}
 
//INPUT
#define tcTUU tcT, class ...U
tcT> void re(complex<T>& c);
tcTU> void re(pair<T,U>& p);
tcT> void re(V<T>& v);
tcT, size_t SZ> void re(AR<T,SZ>& a);
 
tcT> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
tcTUU> void re(T& t, U&... u) { re(t); re(u...); }
 
tcT> void re(complex<T>& c) { T a,b; re(a,b); c = {a,b}; }
tcTU> void re(pair<T,U>& p) { re(p.f,p.s); }
tcT> void re(V<T>& x) { trav(a,x) re(a); }
tcT> void rv(int n, V<T>& x) { x.rsz(n); re(x); }
 
//OUTPUT
namespace output {
	tcT> void PS(V<T>& x) { FOR(i,sz(x)) cout << x[i] << " \n"[i + 1 == sz(x)];}
	tcT> void W(pair<T,T>& x) { cout << x.f << ' ' << x.s << '\n'; }
	tcT> void PS(bool ok) { if(ok) cout << "YES\n"; else cout << "NO\n"; }
    template<class T1, class T2> void pr(const pair<T1,T2>& x);
    tcT, size_t SZ> void pr(const array<T,SZ>& x);
    tcT> void pr(const vector<T>& x);
    tcT> void pr(const set<T>& x);
    template<class T1, class T2> void pr(const map<T1,T2>& x);
 
    tcT> void pr(const T& x) { cout << x; }
    template<class Arg, class... Args> void pr(const Arg& first, const Args&... rest) {
        pr(first); pr(rest...);
    }
 
    template<class T1, class T2> void pr(const pair<T1,T2>& x) {
        pr("{",x.f,", ",x.s,"}");
    }
    tcT> void prContain(const T& x) {
        pr("{");
        bool fst = 1; trav(a,x) pr(!fst?", ":"",a), fst = 0;
        pr("}");
    }
    tcT, size_t SZ> void pr(const array<T,SZ>& x) { prContain(x); }
    tcT> void pr(const vector<T>& x) { prContain(x); }
    tcT> void pr(const set<T>& x) { prContain(x); }
    template<class T1, class T2> void pr(const map<T1,T2>& x) { prContain(x); }
 
    void ps() { pr("\n"); } // print w/ spaces
    template<class Arg> void ps(const Arg& first) { pr(first,"\n"); }
    template<class Arg, class... Args> void ps(const Arg& first, const Args&... rest) {
        pr(first," "); ps(rest...);
    }
}
 
using namespace output;

template<class T,class V> void add(T& a, const V& b) {
	a = (a + b) % MOD;
	}
template<class T,class V> void sub(T& a, const V& b) {
	a = (a - b + MOD) % MOD;
	}
template<class T,class V> void mult(T& a, const V& b) {
	a = a * b % MOD;
	}
 
void setF(string fileName = "") {
	ios_base::sync_with_stdio(0); cin.tie(0);
	if((int)fileName.size()) {
		freopen((fileName+".in").c_str(), "r", stdin);
		freopen((fileName+".out").c_str(), "w", stdout);
	}
}


vb bb;
vi SIEVE(int N){ // sieve in O(N logN)
	vi pr;
	bb.rsz(N);
	bb[0] = bb[1] = true;
	vi g(N);
	F0R(i,2,N){
		if(!bb[i]){
			pr.pb(i);
			for (int j = i + i; j < N; j += i) bb[j] = true;
			}
		}
	return pr;
	}
 


template<class T> using ordset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

struct edge{
	int a;
	int b;
	int w;
	};
 
ll POW(ll x, ll y,ll mod = INF){
    ll res = 1LL;
    x %= mod;
    while(y){
        if (y & 1LL)
            res *= x;
        res %= mod;
        x = (x*x) % mod;
        y >>= 1LL;
    }
    return res;
}
 
ll gauss(ll n) { return n * (n + 1ll) / 2; }
 
ll fact(ll x) { if(x) return x * fact(x - 1ll); return 1; }
 
vl fc;
void F(int N,ll MOD){
	fc.rsz(N + 1);
	fc[0] = 1;
	FORn(i,N) fc[i] = fc[i - 1] * i * 1ll % MOD;
	}
	
vl inv;
void I(int N,ll MOD){
	inv.rsz(N + 1);
	inv[N] = POW(fc[N],MOD - 2,MOD);
	for (int i = N; i ;--i) inv[i - 1] = inv[i] * 1ll * i % MOD;
	}
 
ll Cr(ll N,ll K,ll mod){
	if(K < 0) return 0;
	if(K > N) return 0;
	return fc[N] * 1ll * inv[K] % mod * inv[N - K] % mod;
	}
ll Ar(ll N,ll K,ll mod){
	return fc[N] * inv[N - K] % mod;
	}
ll iv(int k,ll MOD){
  return POW(k,MOD-2,MOD);  
}
/*
 scanf("%lld", &testInteger);
 printf("%lld", testInteger);
 
 ____ ____ ____ ____ ____  ____
||f |||l |||o |||p |||p ||||y ||
||__|||__|||__|||__|||__||||__||
|/__\|/__\|/__\|/__\|/__\||/__\|
 
**/
const int inf = (ll)1e16;
void solve(){
	int N,M; cin >> N >> M;
	V<vpi> A(N + 1),r(N + 1);
	int S,T,U,V; cin >> U >> V >> S >> T;
	while(M--){
		int u,v,c; cin >> u >> v >> c;
		A[u].pb({v,c});
		A[v].pb({u,c});
		}
	auto djs = [&] (int i){
		vi cost(N + 1,inf);
		cost[i] = 0;
		priority_queue<pi,vpi,greater<pi>>pq;
		pq.push({0,i});
		while(sz(pq)){
			auto a = pq.top();
			pq.pop();
			if(a.f > cost[a.s]) continue;
			trav(x,A[a.s])
				if(cost[x.f] > x.s + a.f){
					cost[x.f] = x.s + a.f;
					pq.push({cost[x.f],x.f});
					}
			}
		return cost;
		};
	vi a = djs(T);
	vi b = djs(U);
	vb been(N + 1);
	been[V] = true;
	queue<int>q;
	q.push(V);
	while(sz(q)){
		int i = q.ft;
		q.pop();
		trav(x,A[i])
			if(b[i] - x.s == b[x.f]){
				if(!been[x.f]) q.push(x.f);
				been[x.f] = true;
				r[i].pb({x.f,x.s});
				}
		}
	vvi cost(N + 1,vi(2,inf));
	//ps(r);
	cost[S][0] = 0;
	priority_queue<vi,vvi,greater<vi>>pq;
	pq.push({0,0,S});
	//PS(a);
	int ans = a[S];
	//FOR(i,N){
	//	cout << i << ' ';
	//	ps(r[i]);
	//	}
	while(sz(pq)){
		auto node = pq.top();
		//ps(node);
		pq.pop();
		if(node[0] < 0) continue;
		if(node[0] > cost[node[2]][node[1]]) continue;
		if(node[1]) {
			ckmin(ans,cost[node[2]][1] + a[node[2]]);
			trav(x,r[node[2]])
				if(cost[x.f][1] > node[0]){
					cost[x.f][1] = node[0];
					pq.push({cost[x.f][1],1,x.f});
					}
			}
		else{
			if(sz(r[node[2]])) pq.push({node[0],1,node[2]});
			trav(x,A[node[2]])
				if(cost[x.f][0] > node[0] + x.s){
					cost[x.f][0] = node[0] + x.s;
					pq.push({cost[x.f][0],0,x.f});
					}
			}
		 
		}
	been = vb(N + 1);
	r.clear();
	r.rsz(N + 1);
	q.push(V);
	while(sz(q)){
		int i = q.ft;
		q.pop();
		trav(x,A[i])
			if(b[i] - x.s == b[x.f]){
				if(!been[x.f]) q.push(x.f);
				been[x.f] = true;
				r[x.f].pb({i,x.s});
				}
		}
	pq.push({0,0,S});
	cost = vvi(N + 1,vi(2,inf));
	cost[S][0] = 0;
	while(sz(pq)){
		auto node = pq.top();
		//ps(node);
		pq.pop();
		if(node[0] < 0) continue;
		if(node[0] > cost[node[2]][node[1]]) continue;
		if(node[1]) {
			ckmin(ans,cost[node[2]][1] + a[node[2]]);
			trav(x,r[node[2]])
				if(cost[x.f][1] > node[0]){
					cost[x.f][1] = node[0];
					pq.push({cost[x.f][1],1,x.f});
					}
			}
		else{
			if(sz(r[node[2]])) pq.push({node[0],1,node[2]});
			trav(x,A[node[2]])
				if(cost[x.f][0] > node[0] + x.s){
					cost[x.f][0] = node[0] + x.s;
					pq.push({cost[x.f][0],0,x.f});
					}
			}
		 
		}
	ps(ans);
}
main()
{   setIO();
	solve();
}
// look out for out of bounds arrays
// And more importantly, is y a vowel? Damian:1
// <3 :L ._. <_<
// You have no idea how high I can fly
// code is my poetry

Compilation message (stderr)

commuter_pass.cpp:389:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  389 | main()
      | ^~~~
commuter_pass.cpp: In function 'void setF(std::string)':
commuter_pass.cpp:185:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  185 |   freopen((fileName+".in").c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:186:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  186 |   freopen((fileName+".out").c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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