Submission #1061525

#	Time	Username	Problem	Language	Result	Execution time	Memory
1061525		underwaterkillerwhale	Toll (APIO13_toll)	C++17	16 / 100	92 ms	163840 KiB

toll

#include <bits/stdc++.h>
#define ll long long
#define rep(i,m,n) for(int i=(m); i<=(n); i++)
#define reb(i,m,n) for(int i=(m); i>=(n); i--)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define MP make_pair
#define fs first
#define se second
#define bit(msk, i) ((msk >> i) & 1)
#define iter(id, v) for(auto id : v)
#define pb push_back
#define SZ(v) (int)v.size()
#define ALL(v) v.begin(),v.end()

using namespace std;

mt19937_64 rd(chrono :: steady_clock :: now ().time_since_epoch().count());
ll Rand (ll l, ll r) { return uniform_int_distribution<ll> (l, r) (rd); }

const int N = 1e5 + 2;
const int Mod = 1e9 + 7;
const ll INF = 2e9 + 7;
const ll BASE = 137;
const int szBL = 320;
const int N2 = 1e5 + 7;

struct Disjoint_set_U {
    int lab[N], sz[N];
    void init (int n) {
        rep (i, 1, n) lab[i] = i, sz[i] = 1;
    }
    int Find (int u) {
        return u == lab[u] ? u : lab[u] = Find(lab[u]);
    }
    bool Join (int u, int v) {
        u = Find(u);
        v = Find(v);
        if (u == v) return 0;
        if (sz[u] < sz[v]) swap (u, v);
        sz[u] += sz[v];
        lab[v] = u;
        return 1;
    }
}DSU, DSU2;

struct Edge {
    int u, v, w;
};

int n, m, K;
ll P[N];
pii road[N];
vector<int> ke[N];
int high[N];
ll dp[N];

ll res = 0;
void dfs (int u, int p, ll delta) {
    dp[u] = P[u];
    iter (&v, ke[u]) {
        if (v == p) continue;
        dfs (v, u, delta);
        dp[u] += dp[v];
        pii cur = {u, v};
        if (u > v) swap (u, v);
//        cout << u << " "<<v<<"\n";
        if (MP(u, v) == road[1]) res = dp[v] * delta;
    }

}

void solution () {
    cin >> n >> m >> K;
    vector<Edge> edges;
    rep (i, 1, m) {
        int u, v, w;
        cin >> u >> v >> w;
        edges.pb({u, v, w});
    }
    DSU.init(n);
    sort (ALL(edges), [] (Edge a, Edge b){ return a.w < b.w; });
    ll MST = 0;
    iter (&E, edges) {
        if (DSU.Join(E.u, E.v)) {
            MST += E.w;
        }
    }
    cin >> road[1].fs >> road[1].se;
    rep (i, 1, n) cin >> P[i];
    if (road[1].fs > road[1].se) swap(road[1].fs, road[1].se);
    DSU.init(n);
    DSU.Join(road[1].fs, road[1].se);
    ke[road[1].fs].pb(road[1].se);
    ke[road[1].se].pb(road[1].fs);

    ll MST2 = 0;
    iter (&E, edges) {
        if (DSU.Join(E.u, E.v)) {
            MST2 += E.w;
            ke[E.u].pb(E.v);
            ke[E.v].pb(E.u);

        }
    }
    ll delta = MST - MST2;
//    cout << delta <<"\n";
    dfs(1, 0, delta);
    cout << res <<"\n";
}

#define file(name) freopen(name".inp","r",stdin); \
freopen(name".out","w",stdout);
int main () {
//    file("c");
    ios_base :: sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int num_Test = 1;
//    cin >> num_Test;
    while (num_Test--)
        solution();
}
/*
no bug challenge +2
2 + 8 * 2 - 9
5 5 1
3 5 2
1 2 3
2 3 5
2 4 4
4 3 6
1 3
10 20 30 40 50
*/

Compilation message (stderr)

toll.cpp: In function 'void dfs(int, int, long long int)':
toll.cpp:65:13: warning: variable 'cur' set but not used [-Wunused-but-set-variable]
   65 |         pii cur = {u, v};
      |             ^~~

• Subtask 1: 16 / 16
• Subtask 2: 0 / 18
• Subtask 3: 0 / 22
• Subtask 4: 0 / 22
• Subtask 5: 0 / 22