제출 #1210812

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1210812		qwusha	Radio Towers (IOI22_towers)	C++20	0 / 100	203 ms	3868 KiB

towers

#include <bits/stdc++.h>
#include "towers.h"
using namespace std;
#define fi first
#define se second
typedef long long ll;
typedef long double ld;
mt19937 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());
int inf = 1e9;

int n;
vector<int> h;

vector<int> prefdpsm, prefdpbi;

void init(int N, vector<int> H) {
    n = N;
    h = H;
    prefdpsm.assign(n + 1, 0);
    prefdpbi.assign(n + 1, 0);
    vector<int> smaller(n, -1), bigger(n, -1);
    vector<int> s;
    for (int i = 0; i < n; i++) {
        while (!s.empty() && h[s.back()] >= h[i]) {
            s.pop_back();
        }
        if (!s.empty()) {
            smaller[i] = s.back();
        }
        s.push_back(i);
    }
    s.clear();
    for (int i = 0; i < n; i++) {
        while (!s.empty() && h[s.back()] <= h[i]) {
            s.pop_back();
        }
        if (!s.empty()) {
            bigger[i] = s.back();
        }
        s.push_back(i);
    }
    vector<pair<int, int>> dp(n, {1, 0});
    for (int i = 0; i < n; i++) {
        if (smaller[i] != -1) {
            dp[i].se = max(dp[i].se, dp[smaller[i]].fi);
        }
        if (bigger[i] != -1) {
            dp[i].fi = max(dp[i].fi, dp[bigger[i]].se);
        }
    }
    for (int i = 0; i < n; i++) {
        prefdpsm[i + 1] = max(prefdpsm[i], dp[i].fi);
        prefdpbi[i + 1] = max(prefdpbi[i], dp[i].se);
    }
}

int max_towers(int l, int r, int d) {
    int res = prefdpsm[r + 1] - prefdpbi[l + 1];
    return res;
}

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