Submission #253435

#	Time	Username	Problem	Language	Result	Execution time	Memory
253435		caoash	Cities (BOI16_cities)	C++14	74 / 100	6023 ms	105388 KiB

cities

#pragma GCC target ("sse4")

#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
typedef pair<int, pi> pii;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

#define fax(i, a) for (int i = 0; i < (a); i++)
#define f0x(i, a, b) for (int i = (a); i < (b); i++)
#define f0xd(i,a,b) for (int i = (b)-1; i >= (a); i--)
#define faxd(i,a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto& a : x)
#define memeset memset

#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rsz resize

template<class T> void ckmin(T &a, T b) { a = min(a, b); }
template<class T> void ckmax(T &a, T b) { a = max(a, b); }

template <class T, int ...Ns> struct BIT {
    T val = 0;
    void upd(T v) { val += v; }
    T query() { return val; }
};
 
template <class T, int N, int... Ns> struct BIT<T, N, Ns...> {
    BIT<T,Ns...> bit[N + 1];
    template<typename... Args> void upd(int pos, Args... args) {
        for (; pos <= N; pos += (pos&-pos)) bit[pos].upd(args...);
    }
    template<typename... Args> T sum(int r, Args... args) {
        T res = 0; for (; r; r -= (r&-r)) res += bit[r].query(args...); 
        return res;
    }
    template<typename... Args> T query(int l, int r, Args... args) {
        return sum(r,args...)-sum(l-1,args...);
    }
};

namespace input {
    template<class T> void re(complex<T>& x);
    template<class T1, class T2> void re(pair<T1,T2>& p);
    template<class T> void re(vector<T>& a);
    template<class T, size_t SZ> void re(array<T,SZ>& a);

    template<class T> void re(T& x) { cin >> x; }
    void re(double& x) { string t; re(t); x = stod(t); }
    void re(ld& x) { string t; re(t); x = stold(t); }
    template<class T, class... Ts> void re(T& t, Ts&... ts) { 
        re(t); re(ts...); 
    }

    template<class T> void re(complex<T>& x) { T a,b; re(a,b); x = cd(a,b); }
    template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
    template<class T> void re(vector<T>& a) { fax(i,sz(a)) re(a[i]); }
    template<class T, size_t SZ> void re(array<T,SZ>& a) { fax(i,SZ) re(a[i]); }
}

using namespace input;

namespace output {
    void pr(int x) { cout << x; }
    void pr(long x) { cout << x; }
    void pr(ll x) { cout << x; }
    void pr(unsigned x) { cout << x; }
    void pr(unsigned long x) { cout << x; }
    void pr(unsigned long long x) { cout << x; }
    void pr(float x) { cout << x; }
    void pr(double x) { cout << x; }
    void pr(ld x) { cout << x; }
    void pr(char x) { cout << x; }
    void pr(const char* x) { cout << x; }
    void pr(const string& x) { cout << x; }
    void pr(bool x) { pr(x ? "true" : "false"); }
    
    template<class T1, class T2> void pr(const pair<T1,T2>& x);
    template<class T> void pr(const T& x);
    
    template<class T, class... Ts> void pr(const T& t, const Ts&... ts) { 
        pr(t); pr(ts...); 
    }
    template<class T1, class T2> void pr(const pair<T1,T2>& x) { 
        pr("{",x.f,", ",x.s,"}"); 
    }
    template<class T> void pr(const T& x) { 
        pr("{"); // const iterator needed for vector<bool>
        bool fst = 1; for (const auto& a: x) pr(!fst?", ":"",a), fst = 0; 
        pr("}");
    }
    
    void ps() { pr("\n"); } // print w/ spaces
    template<class T, class... Ts> void ps(const T& t, const Ts&... ts) { 
        pr(t); if (sizeof...(ts)) pr(" "); ps(ts...); 
    }
    
    void pc() { pr("]\n"); } // debug w/ commas
    template<class T, class... Ts> void pc(const T& t, const Ts&... ts) { 
        pr(t); if (sizeof...(ts)) pr(", "); pc(ts...); 
    }
    #define dbg(x...) pr("[",#x,"] = ["), pc(x);
}

using namespace output;

namespace io {
    void setIn(string s) { freopen(s.c_str(),"r",stdin); }
    void setOut(string s) { freopen(s.c_str(),"w",stdout); }
    void setIO(string s = "") {
        ios_base::sync_with_stdio(0); cin.tie(0); // fast I/O
        if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
    }
}

using namespace io;

mt19937 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());

const int MOD = 1000000007; // 998244353
const ll INF = 1e18;
const int MX = 100005;
const ld PI = 4*atan((ld)1);

int n, k; ll dist[5][MX]; vi ord; vpi adj[MX]; bool vis[MX];

void sp(int s){
	priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> pq;
	memeset(vis, false, sizeof(vis));
	int fr = ord[s];
	dist[s][fr] = 0;
	pq.push(mp(0, fr));
	while(!pq.empty()){
		pair<ll, int> curr = pq.top(); pq.pop();
		for(pi to : adj[curr.s]){
			if(!vis[to.f]){
				if(dist[s][to.f] > dist[s][curr.s] + to.s){
					dist[s][to.f] = dist[s][curr.s] + to.s;
					pq.push(mp(dist[s][to.f], to.f));
				}
			}
		}
		vis[curr.s] = true;
	}
}

ll dp[(1 << 5)][MX];
/*
vector<pair<ll, pi>> go(pi &curr){
	vector<pair<ll, pi>> trans;
	for(pi to : adj[curr.f]){
		// dbg(curr.f, to.f, curr.s, to.s);
		trans.pb(mp(to.s, mp(to.f, curr.s)));
	}
	fax(i, k){
		if(!(curr.s & (1 << i))){
			// dbg(curr.f, curr.s, curr.s | (1 << i));
			trans.pb(mp(dist[i][curr.f], mp(curr.f, curr.s | (1 << i))));
		}
	}
	return trans;
}
*/

bool used[(1 << 5)][MX];

void solve(){
	priority_queue<pair<ll, pi>, vector<pair<ll, pi>>, greater<pair<ll, pi>>> pq;
	dp[0][ord[0]] = 0;
	pq.push(mp(0, mp(ord[0], 0)));
	while(!pq.empty()){
		pair<ll, pi> curr = pq.top(); pq.pop();

		for(pi to : adj[curr.s.f]){
			if(!used[curr.s.s][to.f]){
				if(dp[curr.s.s][to.f] > dp[curr.s.s][curr.s.f] + to.s){
					dp[curr.s.s][to.f] = dp[curr.s.s][curr.s.f] + to.s;
					pq.push(mp(dp[curr.s.s][to.f], mp(to.f, curr.s.s)));
				}
			}
		}
		fax(i, k){
			if(!(curr.s.s & (1 << i))){
				int nmask = curr.s.s | (1 << i);
				if(!used[nmask][curr.s.f]){
					if(dp[nmask][curr.s.f] > dp[curr.s.s][curr.s.f] + dist[i][curr.s.f]){
						dp[nmask][curr.s.f] = dp[curr.s.s][curr.s.f] + dist[i][curr.s.f];
						pq.push(mp(dp[nmask][curr.s.f], mp(curr.s.f, nmask)));
					}
				}
			}
		}
		
		/*
		vector<pair<ll, pi>> nxt = go(curr.s);
		// dbg(curr, nxt);
		for(pair<ll, pi> to : nxt){
			if(!used[to.s.s][to.s.f]){
				if(dp[to.s.s][to.s.f] > dp[curr.s.s][curr.s.f] + to.f){
					// dbg(curr.s.f, to.f);
					dp[to.s.s][to.s.f] = dp[curr.s.s][curr.s.f] + to.f;
					pq.push(mp(dp[to.s.s][to.s.f], mp(to.s.f, to.s.s)));
				}
			}
		}
		*/
		used[curr.s.s][curr.s.f] = true;
	}
}

int main() {
    setIO(); 
    int m; re(n, k, m);
    memeset(dist, 0x3f3f3f, sizeof(dist));
    memeset(dp, 0x3f3f3f, sizeof(dp));
    fax(i, k){
    	int x; re(x);
    	ord.pb(x - 1);
    }
    sort(all(ord));
    fax(i, m){
    	int u, v, w; re(u, v, w);
    	u--, v--;
    	adj[u].pb(mp(v, w)), adj[v].pb(mp(u, w));
    }
    fax(i, k) sp(i);
    fax(i, (1 << k)) fax(j, n) dp[i][j] = INF;
    solve();
    ll ans = INF;
    fax(i, n){
    	ckmin(ans, dp[(1 << k) - 1][i]);
    }
    ps(ans);
}

Compilation message (stderr)

cities.cpp: In function 'void io::setIn(std::__cxx11::string)':
cities.cpp:133:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     void setIn(string s) { freopen(s.c_str(),"r",stdin); }
                            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
cities.cpp: In function 'void io::setOut(std::__cxx11::string)':
cities.cpp:134:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     void setOut(string s) { freopen(s.c_str(),"w",stdout); }
                             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 0 / 26