제출 #947218

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
947218		steveonalex	Commuter Pass (JOI18_commuter_pass)	C++11	100 / 100	269 ms	28552 KiB

commuter_pass

#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()

ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}

ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ll mask){return __builtin_ctzll(mask);}
int logOf(ll mask){return __lg(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);}

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, char separator = ' ', char finish = '\n'){
        for(auto item: container) cout << item << separator;
        cout << finish;
    }


template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

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

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

const long N = 1e5 + 69;
const ll INF = 1e18 + 69;
long n, m;
long s, t, u, v;
vector<P> graph[N];
vector<ll> disS, disT, disU, disV;

void dijkstra(long u, vector<ll> &dis){
    dis.resize(n+1);
    for(long i = 1; i<=n; ++i) dis[i] = INF;
    dis[u] = 0;
    priority_queue<P, vector<P>, compare> pq;
    pq.push(P(u, 0));
    while(pq.size()){
        P u = pq.top();
        pq.pop();

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

ll skill_cap;
bool visited[N];
pair<ll, ll> dp[N];

void dfs(long u){
    if (visited[u]) return;
    visited[u] = true;
    dp[u] = {disU[u], disV[u]};
    for(P v: graph[u])
    if (disS[v.i] == disS[u] + v.w && disS[v.i] + disT[v.i] == skill_cap){
        dfs(v.i);
        pair<ll, ll> cur = dp[v.i];
        minimize(cur.first, disU[u]);
        minimize(cur.second, disV[u]);
        if (cur.first + cur.second < dp[u].first + dp[u].second)
            dp[u] = cur;
    }
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    cin >> n >> m;
    cin >> s >> t >> u >> v;
    for(long i = 1; i<=m; ++i){
        long u, v, w; cin >> u >> v >> w;
        graph[u].push_back(P(v, w));
        graph[v].push_back(P(u, w));
    }

    dijkstra(s, disS);
    dijkstra(t, disT);
    dijkstra(u, disU);
    dijkstra(v, disV);

    skill_cap = disS[t];
    ll ans = disU[v];
    dfs(s);
    minimize(ans, dp[s].first + dp[s].second);
    cout << ans << "\n";

    return 0;
}

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