Submission #1124715

#	Time	Username	Problem	Language	Result	Execution time	Memory
1124715		Zero_OP	Paths (RMI21_paths)	C++17	8 / 100	715 ms	589824 KiB

Main

#include <bits/stdc++.h>

using namespace std;

#define rep(i, l, r) for(int i = (l); i < (r); ++i)
#define sz(v) (int)v.size()
#define dbg(x) "[" #x " = " << (x) << "]"
#define all(v) begin(v), end(v)
#define compact(v) v.erase(unique(all(v)), end(v))
#define file(name) if(fopen(name".inp", "r")){ freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }

template<typename T>
    bool minimize(T& a, const T& b){
        if(a > b){
            return a = b, true;
        }
        return false;
    }

template<typename T>
    bool maximize(T& a, const T& b){
        if(a < b){
            return a = b, true;
        }
        return false;
    }

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

using ll = long long;
using ld = long double;
using ull = unsigned long long;
using vi = vector<int>;
using vl = vector<ll>;

const int MAX = 1e5 + 5;

int N, K;
vector<pair<int, int>> adj[MAX];

namespace subtask1{
    bool check(){
        return N <= 18;
    }

    int par[20], par_e[20];
    bool vis[20];
    vector<int> masks;

    void dfs(int u, int p){
        par[u] = p;
        for(auto [v, w] : adj[u]) if(v != p){
            par_e[v] = w;
            dfs(v, u);
        }
    }

    long long calc_up(int u){
        long long s = 0;
        while(!vis[u]){
            vis[u] = true;
            s += par_e[u];
            u = par[u];
        }
        return s;
    }

    long long solve_root(int rt){
        par_e[rt] = 0;
        dfs(rt, -1);

        long long ans = 0;
        for(auto msk : masks){
            fill(vis, vis + N, false);
            vis[rt] = 0;

            long long cur = 0;
            for(int i = 0; i < N; ++i){
                if(msk >> i & 1){
                    cur += calc_up(i);
                }
            }

            ans = max(ans, cur);
        }

        return ans;
    }

    long long ans[20];
    void solve(){
        for(int mask = (1 << K) - 1; mask < (1 << N); ++mask){
            if(__builtin_popcount(mask) == K){
                masks.push_back(mask);
            }
        }

        for(int r = 0; r < N; ++r){
            ans[r] = solve_root(r);
        }

        for(int r = 0; r < N; ++r) cout << ans[r] << '\n';
    }
}

namespace subtask5{
    bool check(){
        return K == 1;
    }

    long long dp_down[MAX], dp_up[MAX];

    void dfs_down(int u, int p){
        for(auto [v, w] : adj[u]) if(v != p){
            dfs_down(v, u);
            maximize(dp_down[u], dp_down[v] + w);
        }
    }

    void dfs_up(int u, int p){
        vector<long long> pref, suff;
        for(auto [v, w] : adj[u]) if(v != p){
            pref.push_back(dp_down[v] + w);
            suff.push_back(dp_down[v] + w);
        }

        for(int i = 1; i < sz(pref); ++i) pref[i] = max(pref[i - 1], pref[i]);
        for(int i = sz(suff) - 2; i >= 0; --i) suff[i] = max(suff[i + 1], suff[i]);

        int i = 0;
        for(auto [v, w] : adj[u]){
            dp_up[v] = dp_up[u];
            if(i > 0) maximize(dp_up[v], pref[i - 1] + w);
            if(i + 1 < sz(suff)) maximize(dp_up[v], suff[i + 1] + w);
            dfs_up(v, u);
        }
    }

    void solve(){
        dfs_down(0, -1);
        dfs_up(0, -1);

        for(int i = 0; i < N; ++i){
            cout << max(dp_down[i], dp_up[i]) << '\n';
        }
    }
}

namespace subtask234{
    bool check(){
        return N <= 2000;
    }

    pair<long long, int> dp[MAX];
    long long ans[2005], sum;
    priority_queue<long long, vector<long long>, greater<long long>> min_pq;

    void add(long long x){
        if((int)min_pq.size() == K){
            if(min_pq.top() < x){
                sum -= min_pq.top();
                min_pq.pop();
                sum += x;
                min_pq.push(x);
            }
        } else{
            sum += x;
            min_pq.push(x);
        }
    }

    void solve(int u, int p){
        dp[u] = {0, u};
        for(auto [v, w] : adj[u]) if(v != p){
            solve(v, u);
            if(dp[u] < make_pair(dp[v].first + w, dp[v].second)){
                dp[u] = make_pair(dp[v].first + w, dp[v].second);
            }
        }

        for(auto [v, w] : adj[u]) if(v != p){
            if(dp[v].second != dp[u].second){
                add(dp[v].first);
            }
        }

        if(p == -1) add(dp[u].first);
    }

    void solve(){
        for(int r = 0; r < N; ++r){
            solve(r, -1);
            ans[r] = sum;
            sum = 0;
            priority_queue<long long, vector<long long>, greater<long long>>().swap(min_pq);
        }

        for(int i = 0; i < N; ++i){
            cout << ans[i] << '\n';
        }
    }
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    file("B");

    cin >> N >> K;
    for(int i = 1; i < N; ++i){
        int u, v, w;
        cin >> u >> v >> w;
        --u, --v;
        adj[u].emplace_back(v, w);
        adj[v].emplace_back(u, w);
    }

    if(subtask1::check()) return subtask1::solve(), 0;
    if(subtask234::check()) return subtask234::solve(), 0;
    if(subtask5::check()) return subtask5::solve(), 0;

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:10:55: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | #define file(name) if(fopen(name".inp", "r")){ freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:208:5: note: in expansion of macro 'file'
  208 |     file("B");
      |     ^~~~
Main.cpp:10:88: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | #define file(name) if(fopen(name".inp", "r")){ freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:208:5: note: in expansion of macro 'file'
  208 |     file("B");
      |     ^~~~

• Subtask 1: 8 / 8
• Subtask 2: 0 / 11
• Subtask 3: 0 / 17
• Subtask 4: 0 / 20
• Subtask 5: 0 / 12
• Subtask 6: 0 / 32