Submission #624898

#	Time	Username	Problem	Language	Result	Execution time	Memory
624898		Lobo	Road Closures (APIO21_roads)	C++17	100 / 100	1348 ms	419180 KiB

roads

#include<iostream>
#include<vector>
#include<cassert>
#include<algorithm>
#include "roads.h"
using namespace std;
#define mp make_pair
#define fr first
#define sc second
#define pb push_back
#define all(x) x.begin(),x.end()
#define sz(x)  int32_t(x.size())
#define int long long
const int maxn = 1e5+10;
const int inf = 1e18+10;
const int mnv = -1e14-10;
const int mxv = 1e14+10;
int n, dp[maxn][2], mark[maxn], atv[maxn];
vector<int> g[maxn], gr[maxn];
vector<pair<int,int>> gesp[maxn];

int cnt[maxn];
vector<int> trq[maxn], trs[maxn], f1[maxn], f2[maxn];
//add/remove pos from id
int att(int no, int l, int r, int id, int pos, int val) {
    if(l > pos || r < pos) return no;
    if(no == 0) {
        no = ++cnt[id]; 
    }
    while(no >= sz(f1[id])) {
        trq[id].pb(0);
        trs[id].pb(0);
        f1[id].pb(0);
        f2[id].pb(0);
    }
    if(l == r) {
        assert(no < sz(trq[id]));
        trq[id][no]+= val;
        assert(no < sz(trs[id]));
        trs[id][no]+= val*pos;
        return no;
    }
    int mid = (l+r)>>1;

    f1[id][no] = att(f1[id][no],l,mid,id,pos,val);
    f2[id][no] = att(f2[id][no],mid+1,r,id,pos,val);
    trq[id][no] = trq[id][f1[id][no]]+trq[id][f2[id][no]];
    trs[id][no] = trs[id][f1[id][no]]+trs[id][f2[id][no]];
    return no;
}

//the sum of the val smallest in (l,r)
int find(int no, int l, int r, int id, int val) {
    
    if(no == 0) return 0;
    if(l == r) {
        return val*r;
    }

    int mid = (l+r)>>1;
    if(trq[id][f1[id][no]] >= val) return find(f1[id][no],l,mid,id,val);
    else return trs[id][f1[id][no]]+find(f2[id][no],mid+1,r,id,val-trq[id][f1[id][no]]);
}

void dfs(int u, int qtd, int ant) {
    mark[u] = 1;
    int ans = 0;
    vector<int> use;
    for(auto V : gesp[u]) if(V.fr != ant) {
        int v = V.fr;
        int w = V.sc;
        dfs(v,qtd,u);
        ans+= min(dp[v][0],dp[v][1]+w);
        use.pb(-min(dp[v][0],dp[v][1]+w)+dp[v][1]+w);
        att(1,mnv,mxv,u,-min(dp[v][0],dp[v][1]+w)+dp[v][1]+w,1);
    }
    dp[u][0] = dp[u][1] = inf;
    if(sz(g[u])-qtd-1 <= 0) dp[u][1] = ans;
    else dp[u][1] = ans+find(1,mnv,mxv,u,sz(g[u])-qtd-1);
    if(sz(g[u])-qtd <= 0) dp[u][0] = ans;
    else dp[u][0] = ans+find(1,mnv,mxv,u,sz(g[u])-qtd);
    for(auto x : use) {
        att(1,mnv,mxv,u,x,-1);
    }
}

std::vector<int> minimum_closure_costs(int32_t N, std::vector<int32_t> U,std::vector<int32_t> V,std::vector<int32_t> W) {
    n = N;
    vector<int> ans;
    int sumw = 0;
    for(int i = 0; i < n-1; i++) {
        int u = U[i];
        int v = V[i];
        int w = W[i];
        sumw+= w;
        g[u].pb(i);
        g[v].pb(i);
    }
    for(int i = 0; i < n; i++) {
        cnt[i] = 1;
        gr[sz(g[i])].pb(i);
    }

    vector<int> esp;
    for(int k = n-1; k >=1; k--) {
        for(auto i : gr[k]) {
            atv[i] = 1;
            esp.pb(i);
            for(auto id : g[i]) {
                int v = i^U[id]^V[id];
                int w = W[id];
                if(atv[v]) {
                    gesp[i].pb(mp(v,w));    
                    gesp[v].pb(mp(i,w)); 
                    att(1,mnv,mxv,v,w,-1);   
                }
                else {
                    att(1,mnv,mxv,i,w,1);
                }
            }
        }

        int ans1 = 0;
        for(auto x : esp) {
            if(!mark[x]) {
                dfs(x,k,-1);
                ans1+= dp[x][0];
            }
        }
        ans.pb(ans1);

        for(auto v : esp) 
            mark[v] = 0;

    }
    ans.pb(sumw);
    reverse(all(ans));

    return ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 14 / 14
• Subtask 4: 10 / 10
• Subtask 5: 17 / 17
• Subtask 6: 25 / 25
• Subtask 7: 22 / 22