Submission #1189282

#	Time	Username	Problem	Language	Result	Execution time	Memory
1189282		guanex	Commuter Pass (JOI18_commuter_pass)	C++20	100 / 100	190 ms	34712 KiB

commuter_pass

#include<bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;

//data structures

typedef pair<ll, ll> ii;
typedef vector<ii> vii;
typedef vector<ll> vll;
typedef vector<ld> vld;
typedef pair<long long, long long> pll;
typedef pair<char, ll> ci;
typedef pair<string, ll> si;
typedef vector<ll> vi;
typedef vector<string> vs;
typedef vector<vector<ll>> vvi;
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define sz(a) ((ll)a.size())
#define fi first
#define se second
#define whole(v) v.begin(), v.end()
#define rwhole(v) v.rbegin(), v.rend()
#define fro front
#define pqueue priority_queue
#define ubound upper_bound
#define lbound lower_bound
#define beg(v) v.begin()

//bit operations

ll flip(ll x){
    return ~(x) ^ (1 << 32);
}

ll allon(ll x){
    return (1LL << x) - 1;
}

bool bit(ll a, ll i){
    return (1LL << i) & a;
}

#define llpc(x) __builtin_popcountll(x)
#define ipc(x) __builtin_popcount(x)
#define iclz(x) __builtin_clz(x)
#define llclz(x) __builtin_clzll(x)
#define ictz(x) __builtin_ctz(x)
#define llctz(x) __builtin_ctzll(x)

//answers

#define cYES cout << "YES" << endl
#define cYes cout << "Yes" << endl
#define cyes cout << "yes" << endl
#define cNO cout << "NO" << endl
#define cNo cout << "No" << endl
#define cno cout << "no" << endl
#define ipsb cout << -1 << endl

const ll mod2 = 998244353;
const ll mod = 1000000007;
const ll inf = ll(1e18);

// read arr vec matr etc

#define fill(x, y) memset(x, y, sizeof(x))

void read(vector<auto> &x){
    for(auto &e:x) cin >> e;
}

void mread(vector<vector<ll>> &p, ll nnn, ll mmm){
    for(ll i = 0; i < nnn; ++i){
        vector<ll> pp;
        for(ll j = 0; j < mmm; ++j){
            ll wq; cin >> wq; pp.pb(wq);
        }
        p.pb(pp);
    }
}

// Solution

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    ll n, m; cin >> n >> m;
    ll s, t; cin >> s >> t;
    ll a, b; cin >> a >> b;
    vector<vii> x(n+1);
    for(ll i = 0; i < m; ++i){
        ll u, v; cin >> u >> v;
        ll cost; cin >> cost;
        x[u].pb({v, cost});
        x[v].pb({u, cost});
    }
    ll pass[n+1];
    ll dist[n+1];
    ll dis[n+1];
    for(ll i = 0; i <= n; ++i){
        dis[i] = inf;
        dist[i] = inf;
        pass[i] = inf;
    }
    pqueue<pair<ll, ii>, vector<pair<ll, ii>>, greater<pair<ll, ii>>> q;
    q.push({0, {s, s}});
    pass[s] = 0;
    ll fat[n+1];
    vvi child(n+1);
    vvi fats(n+1);
    fill(fat, 0);
    int vi[n+1];
    fill(vi, 0);
    while(sz(q)){
        ll no = q.top().se.se;
        ll fa = q.top().se.fi;
        ll cost = q.top().fi;
        q.pop();
        if(pass[no] != cost){
            continue;
        }
        fat[no]++;
        fats[no].pb(fa);
        if(vi[no])continue;
        vi[no] = 1;
        for(auto e:x[no]){
            ll ncost = cost + e.se;
            if(pass[e.fi] >= ncost){
                pass[e.fi] = ncost;
                q.push({ncost, {no, e.fi}});
            }
        }
    }
    queue<ll> bfs;
    bfs.push(t);
    while(sz(bfs)){
        ll no = bfs.fro();
        bfs.pop();
        if(vi[no] == 3)continue;
        vi[no] = 3;
        for(auto e:fats[no]){
            child[e].pb(no);
            if(vi[e] <= 1){
                vi[e] = 2;
                bfs.push(e);
            }
        }
    }


    pqueue<ii, vii, greater<ii>> pq;
    pq.push({0, a});
    dist[a] = 0;
    while(sz(pq)){
        ll no = pq.top().se;
        ll cost = pq.top().fi;
        pq.pop();
        if(dist[no] != cost){
            continue;
        }
        for(auto e:x[no]){
            ll ncost = cost + e.se;
            if(ncost < dist[e.fi]){
                dist[e.fi] = ncost;
                pq.push({ncost, e.fi});
            }
        }
    }
    //cout << "work" << endl;
    pq.push({0, b});
    dis[b] = 0;
    while(sz(pq)){
        ll no = pq.top().se;
        ll cost = pq.top().fi;
        pq.pop();
        if(dis[no] != cost){
            continue;
        }
        for(auto e:x[no]){
            ll ncost = cost + e.se;
            if(ncost < dis[e.fi]){
                dis[e.fi] = ncost;
                pq.push({ncost, e.fi});
            }
        }
    }
    ll ans = dist[b];
    ll dpa[n+1];
    ll dpb[n+1];
    ll dpma[n+1];
    ll dpmb[n+1];
    for(ll i = 0; i <= n; ++i){
        dpa[i] = inf;
        dpb[i] = inf;
        dpma[i] = inf;
        dpmb[i] = inf;
    }
    bfs.push(s);
    dpa[s] = dist[s];
    dpb[s] = dis[s];
    dpma[s] = dpa[s];
    dpmb[s] = dpb[s];
    ll vis[n+1];
    fill(vis, 0);
    while(sz(bfs)){
        ll no = bfs.fro();
        bfs.pop();
        if(vis[no]){
            continue;
        }
        vis[no] = 1;
        for(auto e:child[no]){
            fat[e]--;
            if(fat[e] == 0){
                bfs.push(e);
            }
        }
        ll newa = dist[no];
        ll newb = dis[no];
        ll an = newa + newb;
        dpa[no] = newa;
        dpb[no] = newb;
        dpma[no] = dpa[no];
        dpmb[no] = dpb[no];
        for(auto e:fats[no]){
            dpma[no] = min(dpma[no], dpma[e]);
            dpmb[no] = min(dpmb[no], dpmb[e]);
            ll nan = inf;
            nan = min(nan, dpma[no] + newb);
            if(nan < an){
                dpa[no] = dpma[no];
                dpb[no] = newb;
                an = nan;
            }
            nan = min(nan, dpmb[no] + newa);
            if(nan < an){
                dpa[no] = newa;
                dpb[no] = dpmb[no];
                an = nan;
            }
        }
    }
    for(ll i = 0; i <= n; ++i){
        ans = min(ans, dpa[i] + dpb[i]);
        //cout << ans << " " << i << endl;
    }
    cout << ans << endl;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'll flip(ll)':
commuter_pass.cpp:38:22: warning: left shift count >= width of type [-Wshift-count-overflow]
   38 |     return ~(x) ^ (1 << 32);
      |                    ~~^~~~~

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