Submission #1083110

#	Time	Username	Problem	Language	Result	Execution time	Memory
1083110		steveonalex	Cities (BOI16_cities)	C++17	100 / 100	1344 ms	48200 KiB

cities

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
#define block_of_code if(true)
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

struct P{
    int i; ll w;
    P(){}
    P(int _i, ll _w){
        i = _i, w = _w;
    }
};

struct compare{
    bool operator () (P a, P b){
        return a.w > b.w;
    }
};

const int N = 1e5 + 69;
const ll INF = 1e18 + 69;
int n, k, m;
vector<P> graph[N];
ll dp[MASK(5)][N];

int main(void){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
    clock_t start = clock();

    cin >> n >> k >> m;
    vector<int> important(k);
    for(int i = 0; i<k; ++i) cin >> important[i];

    for(int i = 0; i<m; ++i){
        int u, v, w; cin >> u >> v >> w;
        graph[u].push_back(P(v, w));
        graph[v].push_back(P(u, w));
    }

    for(int mask = 1; mask < MASK(k); ++mask) 
    for(int i = 1; i<=n; ++i){
        dp[mask][i] = INF;
    }

    for(int i = 0; i<k; ++i){
        dp[MASK(i)][important[i]] = 0;
    }

    for(int mask = 1; mask < MASK(k); ++mask){
        for(int _mask = (mask - 1) & mask; _mask > 0; _mask = (_mask - 1) & mask){
            for(int i = 1; i<=n; ++i) minimize(dp[mask][i], dp[_mask][i] + dp[mask - _mask][i]);
        }

        vector<bool> visited(n+1);
        priority_queue<P, vector<P>, compare> pq;
        for(int i = 1; i<=n; ++i) if (dp[mask][i] != INF){
            pq.push(P(i, dp[mask][i]));
        }
        while(pq.size()){
            P u = pq.top(); pq.pop();

            if (visited[u.i]) continue;
            visited[u.i] = true;

            for(P v: graph[u.i]) 
                if (minimize(dp[mask][v.i], dp[mask][u.i] + v.w)){
                    pq.push(P(v.i, dp[mask][v.i]));
                }
        }
    }

    ll ans = INF;
    for(int i= 1; i<=n; ++i) minimize(ans, dp[MASK(k) - 1][i]);
    cout << ans << "\n";


    cerr << "Time elapsed: " << clock() - start << " ms\n";
    return 0;
}

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