Submission #950731

#	Time	Username	Problem	Language	Result	Execution time	Memory
950731		Dec0Dedd	Radio Towers (IOI22_towers)	C++17	11 / 100	17 ms	15956 KiB

towers

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

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

const int N = 2e3+10;

int n, hx[N], mx[N][N];

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

    for (int i=1; i<=n; ++i) {
        mx[i][i]=hx[i];
        for (int j=i+1; j<=n; ++j) mx[i][j]=max(mx[i][j-1], hx[j]);
    }
}

vector<int> G[N];

bool vis[N];
int dfs(int v) {
    vis[v]=true;

    int res=1;
    for (auto u : G[v]) {
        if (vis[u]) continue;
        res+=dfs(u);
    } return res;
}


int max_towers(int l, int r, int d) {
    for (int i=0; i<=n; ++i) G[i].clear();
    ++l, ++r;

    vector<pii> v;
    for (int i=l; i<=r; ++i) v.push_back({hx[i], i});
    sort(v.begin(), v.end());

    bool us[n+1]={};
    for (int i=l; i<=r; ++i) us[i]=true;
    while (!v.empty()) {
        pii x=v.back(); v.pop_back();

        bool ok=true;
        for (int i=l; i<=r; ++i) {
            if (!us[i]) continue;
            if (i == x.second) continue;
            int j=x.second;
            if (abs(i-j) == 1) ok=false;

            if (i < j) {
                if (max(hx[i], hx[j]) > mx[i+1][j-1]-d) ok=false;
            } else {
                if (max(hx[i], hx[j]) > mx[j+1][i-1]-d) ok=false;
            }
        }

        if (!ok) us[x.second]=false;
    }

    int cnt=0;
    for (int i=l; i<=r; ++i) cnt+=us[i];
    return cnt;
}

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