제출 #1179518

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1179518		gyg	Radio Towers (IOI22_towers)	C++20	23 / 100	4053 ms	11092 KiB

towers

#include "towers.h"
#include <bits/stdc++.h>
using namespace std;
#define arr array 
#define vec vector
const int N = 1e5 + 5;

int n;
arr<int, N> h;

void init(int _n, vec<int> _h) {
    n = _n;
    for (int i = 1; i <= n; i++) h[i] = _h[i - 1];
}

int s, f, d;

struct Sgt {
    arr<int, 4 * N> tr;
    void intl() {
        tr.fill(0);
    }
    void upd(int i, int x, int u = 1, int lw = 1, int hg = n) {
        if (lw == hg) { tr[u] += x; return; }
        int md = (lw + hg) / 2;
        if (i <= md) upd(i, x, 2 * u, lw, md);
        else upd(i, x, 2 * u + 1, md + 1, hg);
        tr[u] = max(tr[2 * u], tr[2 * u + 1]);
    }
    int qry(int l, int r, int u = 1, int lw = 1, int hg = n) {
        if (l > r) return 0;
        if (l <= lw && hg <= r) return tr[u];
        int md = (lw + hg) / 2, ans = 0;
        if (l <= md) ans = max(ans, qry(l, r, 2 * u, lw, md));
        if (r > md) ans = max(ans, qry(l, r, 2 * u + 1, md + 1, hg));
        return ans;
    }
} sgt;

arr<int, N> lf, rg;
void prp_cmp() {
    sgt.intl();
    for (int i = 1; i <= n; i++) sgt.upd(i, h[i]);

    for (int i = 1; i <= n; i++) {
        int lw = 1, hg = i;
        while (lw < hg) {
            int md = (lw + hg + 1) / 2;
            if (sgt.qry(md, i) >= h[i] + d) lw = md;
            else hg = md - 1;
        }
        lf[i] = (sgt.qry(lw, i) >= h[i] + d) ? lw : 1;

        lw = i, hg = n;
        while (lw < hg) {
            int md = (lw + hg) / 2;
            if (sgt.qry(i, md) >= h[i] + d) hg = md;
            else lw = md + 1;
        }
        rg[i] = (sgt.qry(i, lw) >= h[i] + d) ? lw : n;
    }

    // for (int i = 1; i <= n; i++) {
    //     cout << i << ": " << lf[i] << " " << rg[i] << '\n';
    // }
}

arr<int, N> dp;
arr<vec<int>, N> add;
void dp_cmp() {
    sgt.intl();
    for (int i = s; i <= f; i++) {
        for (int j : add[i]) 
            sgt.upd(j, dp[j]);
        dp[i] = sgt.qry(s, lf[i] - 1) + 1;
        add[rg[i] + 1].push_back(i);
    }
}

int max_towers(int _s, int _f, int _d) {
    s = _s + 1, f = _f + 1, d = _d;

    prp_cmp();
    dp_cmp();

    int ans = 0;
    for (int i = s; i <= f; i++) ans = max(ans, dp[i]);
    return ans;
}

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