Submission #1070385

#	Time	Username	Problem	Language	Result	Execution time	Memory
1070385		jerzyk	Radio Towers (IOI22_towers)	C++17	100 / 100	1180 ms	28356 KiB

towers

#include <bits/stdc++.h>
#include "towers.h"

using namespace std;
#define pb push_back
#define st first
#define nd second
typedef long long ll;
typedef long double ld;
const ll I = 1000LL * 1000LL * 1000LL * 1000LL * 1000LL * 1000LL;
const int II = 2 * 1000 * 1000 * 1000;
const ll M = 1000LL * 1000LL * 1000LL + 7LL;
const int N = 1<<17;
int drz[2 * N], drz2[2 * N], drz3[2 * N], drz4[2 * N];
int drzmi[2 * N], drzma[2 * N];
vector<int> mrg[2 * N];

int tab[N], ml[N], mr[N], cdi[N], tim[N];
set<int> cur;
set<int>::iterator it;
set<pair<int, int>> dif;


int FindL(int v, int a, int b, int pz, int kz, int x)
{
    if(a > kz || b < pz || drzma[v] < x) return N;
    if(v >= N) return v - N;
    int ans = FindL(v * 2, a, (a + b) / 2, pz, kz, x);
    if(ans < N) return ans;
    ans = FindL(v * 2 + 1, (a + b) / 2 + 1, b, pz, kz, x);
    return ans;
}

int FindR(int v, int a, int b, int pz, int kz, int x)
{
    if(a > kz || b < pz || drzma[v] < x) return 0;
    if(v >= N) return v - N;
    int ans = FindR(v * 2 + 1, (a + b) / 2 + 1, b, pz, kz, x);
    if(ans != 0) return ans;
    ans = FindR(v * 2, a, (a + b) / 2, pz, kz, x);
    return ans;
}

int FindXD(int a, int b, int k)
{
    vector<int> x, y;
    a += N - 1; b += N + 1;
    while(a / 2 != b / 2)
    {
        if(a % 2 == 0) x.pb(a + 1);
        if(b % 2 == 1) y.pb(b - 1);
        a /= 2; b /= 2;
    }
    reverse(y.begin(), y.end());
    for(int j = 0; j < (int)y.size(); ++j) x.pb(y[j]);
    int curmi = II;
    for(int i = 0; i < (int)x.size(); ++i)
    {
        if(drz3[x[i]] >= k || drz[x[i]] - curmi >= k)
        {
            int v = x[i];
            while(v < N)
            {
                v *= 2;
                if(!(drz3[v] >= k || drz[v] - curmi >= k))
                {
                    curmi = min(curmi, drz2[v]);
                    ++v;
                }
            }
            return v - N;
        }
        curmi = min(curmi, drz2[x[i]]);
    }
    return -1;
}

int FindXD2(int a, int b, int k)
{
    vector<int> x, y;
    a += N - 1; b += N + 1;
    while(a / 2 != b / 2)
    {
        if(a % 2 == 0) x.pb(a + 1);
        if(b % 2 == 1) y.pb(b - 1);
        a /= 2; b /= 2;
    }
    reverse(y.begin(), y.end());
    for(int j = 0; j < (int)y.size(); ++j) x.pb(y[j]);
    reverse(x.begin(), x.end());
    int curmi = II;
    for(int i = 0; i < (int)x.size(); ++i)
    {
        if(drz4[x[i]] >= k || drz[x[i]] - curmi >= k)
        {
            int v = x[i];
            while(v < N)
            {
                v = v * 2 + 1;
                if(!(drz4[v] >= k || drz[v] - curmi >= k))
                {
                    curmi = min(curmi, drz2[v]);
                    --v;
                }
            }
            return v - N;
        }
        curmi = min(curmi, drz2[x[i]]);
    }
    return -1;
}

bool ChkL(int a, int b, int k)
{
    //cerr << "Chkl: " << a << " " << b << "\n";
    vector<int> x, y;
    a += N - 1; b += N + 1;
    while(a / 2 != b / 2)
    {
        if(a % 2 == 0) x.pb(a + 1);
        if(b % 2 == 1) y.pb(b - 1);
        a /= 2; b /= 2;
    }
    reverse(y.begin(), y.end());
    for(int j = 0; j < (int)y.size(); ++j) x.pb(y[j]);
    int curmi = II;
    for(int i = 0; i < (int)x.size(); ++i)
    {
        if(drz3[x[i]] >= k) return true;
        if(drz[x[i]] - curmi >= k) return true;
        curmi = min(curmi, drz2[x[i]]);
    }
    return false;
}

bool ChkR(int a, int b, int k)
{
    vector<int> x, y;
    a += N - 1; b += N + 1;
    while(a / 2 != b / 2)
    {
        if(a % 2 == 0) x.pb(a + 1);
        if(b % 2 == 1) y.pb(b - 1);
        a /= 2; b /= 2;
    }
    reverse(y.begin(), y.end());
    for(int j = 0; j < (int)y.size(); ++j) x.pb(y[j]);
    int curma = 0;
    for(int i = 0; i < (int)x.size(); ++i)
    {
        if(drz4[x[i]] >= k) return true;
        if(curma - drz2[x[i]] >= k) return true;
        curma = max(curma, drz[x[i]]);
    }
    return false;
}

void DoT(int n)
{
    drz2[N] = II; drzmi[N] = II;
    for(int i = N; i < 2 * N; ++i)
    {
        drz3[i] = -II / 2;
        drz4[i] = -II / 2;
    }
    for(int i = 1; i <= n; ++i)
    {
        drzmi[i + N] = tim[i]; drzma[i + N] = tim[i];
        drz[i + N] = tab[i]; drz2[i + N] = tab[i];
        mrg[i + N] = {tim[i]};
    }
    for(int i = n + 1; i < N; ++i)
    {drzmi[i + N] = II; drz2[i + N] = II;}

    for(int i = N - 1; i >= 1; --i)
    {
        drzma[i] = max(drzma[2 * i], drzma[2 * i + 1]);
        drzmi[i] = min(drzmi[2 * i], drzmi[2 * i + 1]);

        drz[i] = max(drz[2 * i], drz[2 * i + 1]);
        drz2[i] = min(drz2[2 * i], drz2[2 * i + 1]);

        drz3[i] = max(drz3[i * 2], drz3[i * 2 + 1]);
        drz3[i] = max(drz3[i], drz[i * 2 + 1] - drz2[i * 2]);

        drz4[i] = max(drz4[i * 2], drz4[i * 2 + 1]);
        drz4[i] = max(drz4[i], drz[i * 2] - drz2[i * 2 + 1]);

        mrg[i] = mrg[i * 2];
        for(int j = 0; j < (int)mrg[i * 2 + 1].size(); ++j)
            mrg[i].pb(mrg[i * 2 + 1][j]);
        sort(mrg[i].begin(), mrg[i].end());
    }
}

inline int Il(int v, int x)
{
    return (mrg[v].end() - lower_bound(mrg[v].begin(), mrg[v].end(), x));
}

int Query(int a, int b, int x)
{
    a += N - 1; b += N + 1;
    int ans = 0;
    while(a / 2 != b / 2)
    {
        if(a % 2 == 0) ans += Il(a + 1, x);
        if(b % 2 == 1) ans += Il(b - 1, x);
        a /= 2; b /= 2;
    }

    return ans;
}

int GetL(int v)
{
    it = cur.lower_bound(v);
    if(it == cur.begin()) return 0;
    --it; return *it;
}

int GetR(int v)
{
    it = cur.upper_bound(v);
    if(it == cur.end()) return 0;
    return *it;
}

void init(int _N, vector<int> _H)
{
    int n = _N;
    for(int i = 1; i <= n; ++i) tab[i] = _H[i - 1];
    for(int i = 1; i <= n; ++i)
    {
        ml[i] = 0LL; mr[i] = 0LL;
        cur.insert(i);
    }
    ml[1] = II; mr[n] = II;
    for(int i = 1; i <= n; ++i)
    {
        cdi[i] = min(ml[i], mr[i]) - tab[i];
        dif.insert(make_pair(cdi[i], i));
    }
    while((int)cur.size() > 1)
    {
        int v = (*dif.begin()).nd;
        dif.erase(dif.begin());
        cur.erase(v);
        tim[v] = cdi[v];
        int l = GetL(v), r = GetR(v);
        int xd = max(tab[v], max(mr[v], ml[v]));
        if(l != 0)
        {
            dif.erase(make_pair(cdi[l], l));
            mr[l] = max(mr[l], xd);
            cdi[l] = min(ml[l], mr[l]) - tab[l];
            dif.insert(make_pair(cdi[l], l));
        }
        if(r != 0)
        {
            dif.erase(make_pair(cdi[r], r));
            ml[r] = max(ml[r], xd);
            cdi[r] = min(ml[r], mr[r]) - tab[r];
            dif.insert(make_pair(cdi[r], r));
        }
    }
    for(int i = 1; i <= n; ++i)
        tim[i] = max(tim[i], 0);
    tim[*cur.begin()] = II;
    DoT(n);
    //for(int i = 1; i <= n; ++i)
        //cerr << tim[i] << " ";
    //cerr << "\n";
}

int max_towers(int L, int R, int D)
{
    ++L; ++R;
    int ans = Query(L, R, D);
    if(ans == 0)
    {
        int p = FindXD(L, R, D);
        int p2 = FindXD2(L, R, D);
        //cerr << "Find: " << p << " " << QueryMI(p + 1, R) << "\n";
        if(p == -1 || p2 == -1) return 1;
        if(p <= p2) return 2;
        return 1;
    }
    int l = FindL(1, 0, N - 1, L, R, D);
    int r = FindR(1, 0, N - 1, L, R, D);
    //cerr << "Que: " << l << " " << r << "\n";
    if(l != L && ChkL(L, l - 1, D)) ++ans;
    if(r != R && ChkR(r + 1, R, D)) ++ans;
    return ans;
}

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