Submission #1203369

#	Time	Username	Problem	Language	Result	Execution time	Memory
1203369		Zbyszek99	Radio Towers (IOI22_towers)	C++20	60 / 100	4021 ms	382864 KiB

towers

#include "towers.h"
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define vi vector<int>
#define vl vector<long long>
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace std;
//mt19937 mt;void random(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll rand(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

const int tree_siz = 1024*256-1;

struct node
{
    node* left;
    node* right;
    bool is_sons = 0;
    int oper = 0;
    ll l = 0;
    ll r = (1 << 30)-1;
    void upd_sons()
    {
        if(!is_sons)
        {
            left = new node;
            right = new node;
            left -> l = l;
            left -> r = (l+r)/2;
            right -> l = (l+r)/2+1;
            right -> r = r;
        }
        is_sons = 1;
    }
    int get_sum(int poz)
    {
        int ans = oper;
        //cout << l << " " << r << " " << oper << " " << poz << " query\n";
        if(l != r)
        {
            upd_sons();
            if(poz <= (l+r)/2) ans += left -> get_sum(poz);
            else ans += right -> get_sum(poz);
        }
        return ans;
    }
    void add_seg(int l2, int r2, int w, node& prev_node)
    {
       // cout << l << " " << r << " " << l2 << " " << r2 << " " << w << " add\n";
        if(l >= l2 && r <= r2)
        {
            if(l != r)
            {
                prev_node.upd_sons();
                is_sons = 1;
                left = prev_node.left;
                right = prev_node.right;
            }
            oper = prev_node.oper + w;
            return;
        }
        ll left_l = l;
        ll left_r = (l+r)/2;
        ll right_l = (l+r)/2+1;
        ll right_r = r;
        is_sons = 1;
        prev_node.upd_sons();
        if(left_r < l2 || left_l > r2)
        {
            left = prev_node.left;
        }
        else
        {
            left = new node;
            left -> l = left_l;
            left -> r = left_r;
            left -> oper = prev_node.left->oper;
            left -> add_seg(l2,r2,w,*prev_node.left);
        }
        if(right_r < l2 || right_l > r2)
        {
            right = prev_node.right;
        }
        else
        {
            right = new node;
            right -> l = right_l;
            right -> r = right_r;
            right -> oper = prev_node.right->oper;
            right -> add_seg(l2,r2,w,*prev_node.right);
        }
    }
};

struct mmtree
{
    pii dmax[tree_siz+1];
    pii dmin[tree_siz+1];
    void setup(vi arr)
    {
        rep(i,siz(arr))
        {
            dmax[tree_siz/2+1+i] = {arr[i],i};
            dmin[tree_siz/2+1+i] = {arr[i],i};
        }
        rep2(i,tree_siz/2+1+siz(arr),tree_siz)
        {
            dmax[i] = {-2e9,i};
            dmin[i] = {2e9,i};
        }
        for(int i = tree_siz/2; i >= 1; i--)
        {
            dmax[i] = max(dmax[i*2],dmax[i*2+1]);
            dmin[i] = min(dmin[i*2],dmin[i*2+1]);
        }
    }
    pair<pii,pii> query(int akt, int p1, int p2, int s1, int s2)
    {
        if(p2 < s1 || p1 > s2) return {{2e9,1},{-2e9,1}};
        if(p1 >= s1 && p2 <= s2) return {dmin[akt],dmax[akt]};
        pair<pii,pii> w1 = query(akt*2,p1,(p1+p2)/2,s1,s2);
        pair<pii,pii> w2 = query(akt*2+1,(p1+p2)/2+1,p2,s1,s2);
        return {min(w1.ff,w2.ff),max(w1.ss,w2.ss)};
    }
    pair<pii,pii> get_info(int l, int r)
    {
        return query(1,0,tree_siz/2,l,r);
    }
};

int n;

int left_D[100'001];
int right_D[100'001];
mmtree mtree;
node trees[100'001];

void init(int N, vi H) 
{
    n = N;
    mtree.setup(H);
    vector<pii> sort_poz;
    rep(i,n) sort_poz.pb({H[i],i});
    sort(all(sort_poz));
    set<int> s;
    forall(it,sort_poz)
    {
        auto ptr = s.lower_bound(it.ss);
        if(ptr == s.end())
        {
            right_D[it.ss] = 1e9;
        }
        else
        {
            int nxt = *ptr;
            int max_ = mtree.get_info(it.ss,nxt-1).ss.ff;
            right_D[it.ss] = max_ - it.ff; 
        }
        if(ptr == s.begin())
        {
            left_D[it.ss] = 1e9;
        }
        else
        {
            ptr--;
            int prev = *ptr;
            int max_ = mtree.get_info(prev+1,it.ss).ss.ff;
            left_D[it.ss] = max_-it.ff;
        }
        s.insert(it.ss);
    }
    rep(i,n)
    {
        int min_d = min(left_D[i],right_D[i]);
        trees[i+1].add_seg(0,min_d,1,trees[i]);
    }
}

int max_towers(int L, int R, int D) 
{
    int beg_val = trees[L].get_sum(D);
    int end_val = trees[R+1].get_sum(D);
    int ans = end_val - beg_val;
    int first_ = 1e9;
    int last_ = 0;
    if(ans == 0)
    {
        int min_poz = mtree.get_info(L,R).ff.ss;
        ans++;
        last_ = min_poz;
        first_ = min_poz;
    }
    else
    {
        int l = L;
        int r = R;
        while(l <= r)
        {
            int mid = (l+r)/2;
            if(trees[mid+1].get_sum(D) - beg_val >= 1)
            {
                first_ = mid;
                r = mid-1;
            }
            else
            {
                l = mid+1;
            }
        }
        l = L;
        r = R;
        while(l <= r)
        {
            int mid = (l+r)/2;
            if(end_val - trees[mid].get_sum(D) >= 1)
            {
                last_ = mid;
                l = mid+1;
            }
            else
            {
                r = mid-1;
            }
        }
    }
    rep2(i,L,first_-1)
    {
        if(right_D[i] >= D)
        {
            ans++;
            break;
        }
    }
    rep2(i,last_+1,R)
    {
        if(left_D[i] >= D)
        {
            ans++;
            break;
        }
    }
    return ans;
}

• Subtask 1: 4 / 4
• Subtask 2: 11 / 11
• Subtask 3: 12 / 12
• Subtask 4: 14 / 14
• Subtask 5: 0 / 17
• Subtask 6: 19 / 19
• Subtask 7: 0 / 23