Submission #618504

#	Time	Username	Problem	Language	Result	Execution time	Memory
618504		Do_you_copy	Toll (APIO13_toll)	C++17	16 / 100	3 ms	2644 KiB

toll

#include <bits/stdc++.h>
#define taskname "test"
#define fi first
#define se second
#define pb push_back
#define faster ios_base::sync_with_stdio(0); cin.tie(0);
using namespace std;
using ll = long long;
using ull = unsigned ll;
using ld = long double;
using pii = pair <int, int>;
using pil = pair <int, ll>;
using pli = pair <ll, int>;
using pll = pair <ll, ll>;
mt19937 Rand(chrono::steady_clock::now().time_since_epoch().count());

ll min(const ll &a, const ll &b){
    return (a < b) ? a : b;
}

ll max(const ll &a, const ll &b){
    return (a > b) ? a : b;
}

//const ll Mod = 1000000007;
//const ll Mod2 = 999999999989;
//only use when required
const int maxN = 1e5 + 1;
const int maxM = 3e5 + 1;
const int maxK = 21;
const int inf = 0x3f3f3f3f;
int n, m, k;

struct TEdge{
    int u, v, w;
    bool operator < (const TEdge &other){
        return w < other.w;
    }
};
TEdge a[maxM + maxK];

vector <int> edge;
struct TDSU{
    vector <int> lab;
    TDSU(){}
    TDSU(int _n){
        lab.resize(_n, -1);
    }
    inline void resize(int _n){
        lab.resize(_n, -1);
    }
    inline int find(int u){
        if (lab[u] < 0) return u;
        return lab[u] = find(lab[u]);
    }
    inline void merge(int u, int v){
        if (lab[u] > lab[v]) swap(u, v);
        lab[u] += lab[v];
        lab[v] = u;
    }
    inline void clear(){
        lab.clear();
    }
    inline void reset(int _n){
        clear();
        resize(_n);
    }
};

TDSU dsu;
int p[maxN];
int id[22];
int depth[22];
int node_cnt = 0;
ll sum[22];
vector <TEdge> required;
bool mark[22];
ll res = 0;
vector <pii> adj[maxN];
ll sm[22];
int par[22];
bool visited[22];

void dfs(int u, int p){
    sm[u] = sum[u];
    par[u] = p;
    depth[u] = depth[p] + 1;
    for (auto i: adj[u]){
        if (i.fi == p) continue;
        if (i.se != -inf) mark[i.fi] = 1;
        dfs(i.fi, u);
        sm[u] += sm[i.fi];
    }
    adj[u].clear();
}

void update(int u, int v, int w){
    if (depth[u] < depth[v]) swap(u, v);
    while (depth[u] != depth[v]){
        if (!mark[u]) res += sm[u] * w;
        sm[u] = 0;
        u = par[u];
    }
    while (u != v){
        if (!mark[u]) res += sm[u] * w;
        if (!mark[v]) res += sm[v] * w;
        sm[u] = sm[v] = 0;
        u = par[u];
        v = par[v];
    }
}

ll cal(int mask){
    res = 0;
    fill(visited, visited + node_cnt + 1, 0);
    dsu.reset(node_cnt + 1);
    for (int i = 1; i <= node_cnt; ++i)
    while (mask){
        int t = mask & -mask;
        int i = __lg(t) + 1;
        int u = a[i].u; int v = a[i].v;
        int x = dsu.find(u), y = dsu.find(v);
        if (x == y){
            return 0;
        }
        dsu.merge(x, y);
        adj[u].pb({v, -inf});
        adj[v].pb({u, -inf});
        mask -= t;
    }
    vector <TEdge> check;
    for (auto i: required){
        int x = dsu.find(i.u), y = dsu.find(i.v);
        if (x != y){
            dsu.merge(x, y);
            adj[i.u].pb({i.v, i.w});
            adj[i.v].pb({i.u, i.w});
        }
        else check.pb(i);
    }
    dfs(1, 0);
    for (auto i: check){
        update(i.u, i.v, i.w);
    }
    return res;
}

void Init(){
    cin >> n >> m >> k;
    for (int i = k + 1; i <= m + k; ++i){
        cin >> a[i].u >> a[i].v >> a[i].w;
    }
    for (int i = 1; i <= k; ++i){
        cin >> a[i].u >> a[i].v;
        a[i].w = -inf;
    }
    for (int i = 1; i <= n; ++i) cin >> p[i];
    sort(a + k + 1, a + m + k + 1);
    dsu.reset(n + 1);
    for (int i = 1; i <= k; ++i){
        int u = a[i].u, v = a[i].v;
        int x = dsu.find(u), y = dsu.find(v);
        if (x != y){
            dsu.merge(x, y);
        }
    }
    for (int i = k + 1; i <= m + k; ++i){
        int u = a[i].u, v = a[i].v;
        int x = dsu.find(u), y = dsu.find(v);
        if (x != y){
            edge.pb(i);
            dsu.merge(x, y);
        }
    }
    dsu.reset(n + 1);
    for (const int &i: edge){
        int u = a[i].u, v = a[i].v;
        int x = dsu.find(u), y = dsu.find(v);
        dsu.merge(x, y);
    }
    for (int i = 1; i <= n; ++i){
        int j = dsu.find(i);
        if (!id[j]) id[j] = ++node_cnt;
        sum[id[i] = id[j]] += p[i];
    }
    for (int i = 1; i <= k + m; ++i){
        a[i].u = id[a[i].u];
        a[i].v = id[a[i].v];
    }
    dsu.reset(node_cnt + 1);
    edge.clear();
    for (int i = k + 1; i <= k + m; ++i){
        int u = a[i].u, v = a[i].v;
        int x = dsu.find(u), y = dsu.find(v);
        if (x != y){
            edge.pb(i);
            dsu.merge(x, y);
        }
    }
    for (const int &i: edge) required.pb(a[i]);
    ll ans = 0;
    for (int i = 1; i < 1 << k; ++i){
        ans = max(ans, cal(i));
    }
    cout << ans;
}


int main(){
    if (fopen(taskname".inp", "r")){
        freopen(taskname".inp", "r", stdin);
        //freopen(taskname".out", "w", stdout);
    }
    faster;
    ll tt = 1;
    //cin >> tt;
    while (tt--){
        Init();
    }
}

Compilation message (stderr)

toll.cpp: In function 'int main()':
toll.cpp:211:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  211 |         freopen(taskname".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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