제출 #1225215

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1225215		Bui_Quoc_Cuong	통행료 (APIO13_toll)	C++20	0 / 100	6 ms	9792 KiB

toll

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int MAX = 3e5 + 5;

int n, m, k;
struct Edges{
    int u, v, w; 
} MST[MAX], SE[MAX], E[MAX];
int c[MAX];

vector <int> g[MAX];
int weight[MAX], par[MAX], h[MAX];
int sz[MAX];
int lab[MAX];
vector <array <int, 3>> edges;
bool in_MST[MAX];

int find(int x){
    return lab[x] < 0 ? x : lab[x] = find(lab[x]);
}

bool joint(int u, int v){
    int x = find(u), y = find(v);
    if(x == y) return false;
    if(lab[x] > lab[y]) swap(x, y);
    lab[x]+= lab[y];
    lab[y] = x;
    return true;
}

void reset_dsu(){
    memset(lab, - 1, sizeof lab);
}

void dfs(int u, int p){
    sz[u] = c[u];
    for(int v : g[u]) if(v != p){
        par[v] = u;
        h[v] = h[u] + 1;
        dfs(v, u);
        sz[u]+= sz[v];
    }
}

void update_edge(int u, int v, int w){
    if(h[u] < h[v]) swap(u, v);
    while(h[u] > h[v]){
        weight[u] = min(weight[u], w);
        u = par[u];
    }
    while(u != v){
        weight[u] = min(weight[u], w);
        weight[v] = min(weight[v], w);
        u = par[u], v = par[v];
    }
}

namespace sub123{

    void solve(){
        ll ans = 0;
        reset_dsu();

        for(int mask = 0; mask < (1 << k); mask++){
            bool ok = 1;
            for(int i = 1; i <= n; i++) g[i].clear(), lab[i] = - 1, weight[i] = 2e9, in_MST[i] = 0;

            for(int i = 0; i < k; i++) if((mask >> i) & 1){
                if(!joint(SE[i + 1].u, SE[i + 1].v)){
                    ok = false;
                    break;
                }
                if((mask >> i) & 1){
                    g[SE[i + 1].u].push_back(SE[i + 1].v);
                    g[SE[i + 1].v].push_back(SE[i + 1].u);
                }
            }

            if(!ok) continue;   

            for(int i = 1; i <= n - 1; i++){
                if(joint(MST[i].u, MST[i].v)){
                    in_MST[i] = 1;
                    g[MST[i].u].push_back(MST[i].v);
                    g[MST[i].v].push_back(MST[i].u);
                }
            }   

            dfs(1, - 1);
            for(int i = 1; i <= n; i++) if(!in_MST[i]){
                update_edge(MST[i].u, MST[i].v, MST[i].w);
            }

            ll sum = 0;
            for(int i = 0; i < k; i++) if((mask >> i) & 1){
                int u = SE[i + 1].u, v = SE[i + 1].v;
                if(h[u] > h[v]) swap(u, v);
                sum+= 1LL * weight[v] * sz[v];
            }
            ans = max(ans, sum);
        }   
        cout << ans;
    }   
}

namespace sub45{
    int color[MAX], cnt;
    void dfs(int u, int col){
        color[u] = col;
        for(int v : g[u]) if(color[v] == - 1){
            dfs(v, col);
        }
    }
    ll sum_c[MAX];
    ll SUM[MAX];

    void DFS(int u, int p){
        SUM[u] = sum_c[u];
        for(int v : g[u]) if(v != p){
            DFS(v, u);
            SUM[u]+= SUM[v];
        }
    }

    void solve(){
        reset_dsu();
        for(int i = 1; i <= k; i++){
            joint(SE[i].u, SE[i].v);
        }
        sort(E + 1, E + 1 + m, [&](Edges u, Edges v){
            return u.w < v.w;
        });
        for(int i = 1; i <= m; i++) if(joint(E[i].u, E[i].v)){
            g[E[i].u].push_back(E[i].v);
            g[E[i].v].push_back(E[i].u);
            in_MST[i] = 1;
        }

        reset_dsu();
        vector <Edges> extra;
        for(int i = 1; i <= m; i++) if(in_MST[i]){
            joint(E[i].u, E[i].v);
        }
        for(int i = 1; i <= m; i++) if(!in_MST[i]){
            if(joint(E[i].u, E[i].v)){
                extra.push_back(E[i]);
            }
        }

        memset(color, - 1, sizeof color);
        for(int i = 1; i <= n; i++) if(color[i] == - 1){
            cnt++;
            dfs(i, cnt);
        }

        for(int i = 1; i <= k; i++) SE[i].u = color[SE[i].u], SE[i].v = color[SE[i].v];
        for(auto &x : extra) x.u = color[x.u], x.v = color[x.v]; 
        for(int i = 1; i <= n; i++) sum_c[color[i]]+= c[i]; 

        ll ans = 0;

        for(int mask = 0; mask < (1 << k); mask++){
            for(int i = 1; i <= cnt; i++) g[i].clear(), lab[i] = - 1, weight[i] = 2e9;
            bool ok = 1;
            for(int i = 0; i < k; i++) if((mask >> i) & 1){
                if(!joint(SE[i + 1].u, SE[i + 1].v)){
                    ok = 1;
                    break;
                }
                if((mask >> i) & 1){
                    g[SE[i + 1].u].push_back(SE[i + 1].v);
                    g[SE[i + 1].v].push_back(SE[i + 1].u);
                }
            }
            if(!ok) continue;   

            for(auto x : extra){
                if(joint(x.u, x.v)){
                    g[x.u].push_back(x.v);
                    g[x.v].push_back(x.u);
                }
            }

            DFS(1, - 1);

            for(auto x : extra){
                update_edge(x.u, x.v, x.w);
            }

            ll sum = 0;
            for(int i = 0; i < k; i++) if((mask >> i) & 1){
                int u = SE[i + 1].u, v = SE[i + 1].v;
                if(h[u] > h[v]) swap(u, v);
                sum+= 1LL * weight[v] * SUM[v];
            }
            ans = max(ans, sum);
        }
        cout << ans;
    }   
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    freopen("kieuoanh.inp", "r", stdin);
    freopen("kieuoanh.out", "w", stdout);

    cin >> n >> m >> k;
    for(int i = 1; i <= m; i++){
        int u, v, w; cin >> u >> v >> w;
        edges.push_back({w, u, v});
        E[i] = {u, v, w};
    }
    for(int i = 1; i <= k; i++) cin >> SE[i].u >> SE[i].v;
    for(int i = 1; i <= n; i++) cin >> c[i];

    reset_dsu();
    sort(edges.begin(), edges.end());

    int cnt = 0;
    for(array <int, 3> it : edges){
        int u = it[1], v = it[2], w = it[0];
        if(joint(u, v)){
            MST[++ cnt] = {u, v, w};
        }
    }   
        
    /// thay vì ta duyệt lại từng cạnh để check thì có nhận xét
    /*
        ta nén cây lại

        xét k cạnh đặc biệt 

        MST 1 gôm : k cạnh đặc biệt + cạnh mặc định
        MST 2 gồm : cạnh mặc định
        từ đó ta có những cạnh có khả năng cạnh tranh 
    */

    return sub45::solve(), 0;
    
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

toll.cpp: In function 'int main()':
toll.cpp:206:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  206 |     freopen("kieuoanh.inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
toll.cpp:207:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  207 |     freopen("kieuoanh.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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