Submission #873478

#	Time	Username	Problem	Language	Result	Execution time	Memory
873478		sleepntsheep	Paths (RMI21_paths)	C++17	48 / 100	336 ms	18004 KiB

Main

#include <cstdio>
#include <cstring>
#include <cassert>
#include <string>
#include <deque>
#include <vector>
#include <map>
#include <queue>
#include <algorithm>
#include <iostream>
#include <utility>
using namespace std;
using ll = long long;
using ld = long double;
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false)

#define N 200005
#define ALL(x) x.begin(), x.end()

int n, k;
vector<pair<int, int>> g[N];

namespace sub123
{
    ll dp[1001][101];
    int sz[N];

    void dfs1(int u, int p)
    {
        dp[u][0] = dp[u][1] = 0;
        sz[u] = 1;
        for (auto [w, v] : g[u]) if (v != p)
        {
            dfs1(v, u);
            for (int i = sz[u]; i >= 0; --i)
                for (int j = 1; i+j <= k && j <= sz[v]; ++j)
                    dp[u][i+j] = max(dp[u][i+j], dp[u][i] + dp[v][j] + w);
            sz[u] += sz[v];
        }
    }

    ll oneroot(int u)
    {
        memset(dp, 0xbf, sizeof dp);
        dfs1(u, u);
        return dp[u][k];
    }
};

namespace sub5
{
    ll dp2[N], dp3[N], dp4[N];
    void dfs2(int u, int p)
    {
        dp2[u] = 0;
        for (auto [w, v] : g[u]) if (v != p)
        {
            dfs2(v, u);
            if (dp2[v] + w >= dp2[u]) dp3[u] = dp2[u], dp2[u] = dp2[v] + w;
            else if (dp2[v] + w >= dp3[u]) dp3[u] = dp2[v] + w;
        }
    }

    void dfs3(int u, int p)
    {
        for (auto [w, v] : g[u]) if (v != p)
        {
            if (dp2[v] + w == dp2[u]) dp4[v] = max(dp4[u] + w, dp3[u] + w);
            else dp4[v] = max(dp4[u] + w, dp2[u] + w);
            dfs3(v, u);
        }
    }
};

namespace sub4
{
    int tin[2001], tout[2001], timer, P[2001][2], rv[2001];
    ll rt[N]{0};

    struct segtree
    {
        pair<ll, int> t[4005]; ll lz[4005]{0};
        segtree() { }

        void build(int v, int l, int r)
        {
            lz[v]=0;
            if (l >= r) {
                int u = rv[l];
                if (tin[u]==tout[u]) t[v] = {rt[u], u};
                else t[v] = {-0,u};
                return;
            }
            int m = (l+r)/2,vl=v+1,vr=v+(m-l+1)*2;
            build(vl,l,m),build(vr,m+1,r);
            t[v]=max(t[vl],t[vr]);
        }

        void push(int v, int l, int r)
        {
            if (!lz[v])return;
            if(l-r)
            {
                int m = (l+r)/2,vl=v+1,vr=v+(m-l+1)*2;
                lz[vl]+=lz[v];lz[vr]+=lz[v];
            }
            lz[v]=0;
        }

        pair<ll, int> qry(int x, int y, int v, int l, int r)
        {
            push(v,l,r);
            if (y<l||r<x) return {-1e18, -1e9};
            if (x<=l&&r<=y){return t[v];}
            int m = (l+r)/2,vl=v+1,vr=v+(m-l+1)*2;
            return max(qry(x, y, vl,l,m),qry(x,y,vr,m+1,r));
        }

        void upd(int x, int y, int k, int v, int l, int r)
        {
            push(v,l,r);
            if (y<l||r<x) return;
            if (x<=l&&r<=y){lz[v]=k;push(v,l,r);return;}
            int m = (l+r)/2,vl=v+1,vr=v+(m-l+1)*2;
            upd(x, y,k,vl,l,m),upd(x,y,k,vr,m+1,r);
            t[v]=max(t[vl],t[vr]);
        }
    } t;

    void dfs1(int u, int p)
    {
        rv[tin[u] = timer++] = u;
        for (auto [w, v] : g[u]) if (v-p) P[v][0]=u,P[v][1]=w,rt[v]=rt[u]+w,dfs1(v, u);
        tout[u] = timer - 1;
    }

    ll ans;
    int del[2010]{0};
    void process()
    {
        pair<ll,int> x = t.qry(0,n-1,0,0,n-1);
        if (x.first <= 0) return;
        ans += x.first;
        for (int c = x.second; c; c = P[c][0])
        {
            int p = P[c][0], w = P[c][1];
            if(!del[c]) t.upd(tin[c], tout[c], -w, 0, 0, n-1),del[c]=1;
        }
    }

    ll oneroot(int root)
    {
        memset(rt,0,sizeof rt);
        memset(rv,0,sizeof rv);
        memset(del,0,sizeof del);
        memset(P,0,sizeof P);
        rt[root]=ans=timer=0;
        dfs1(root,root);
        t.build(0,0,n-1);
        for (int i = 1; i <= k; ++i) process();
        return ans;
    }

};

int main()
{
    ShinLena;
    cin >> n >> k;
    for (int u, v, w, i = 1; i < n; ++i) cin >> u >> v >> w, g[u].emplace_back(w, v), g[v].emplace_back(w, u);

    if (k == 1)
    {
        sub5::dfs2(1, 1);
        sub5::dfs3(1, 1);
        for (int i = 1; i <= n; ++i) cout << max(sub5::dp2[i], sub5::dp4[i]) << '\n';
    }
    else if (n <= 1002)
    {
        for (int i = 1; i <= n; ++i) cout << sub123::oneroot(i) << '\n';
    }
    else if (n <= 2000)
    {
        for (int i = 1; i <= n; ++i) cout << sub4::oneroot(i) << '\n';
    }
    else
    {
    }

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void sub4::process()':
Main.cpp:146:17: warning: unused variable 'p' [-Wunused-variable]
  146 |             int p = P[c][0], w = P[c][1];
      |                 ^

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