Submission #1082589

#	Time	Username	Problem	Language	Result	Execution time	Memory
1082589		Wansur	Radio Towers (IOI22_towers)	C++17	0 / 100	4030 ms	11900 KiB

towers

#include "towers.h"
#include <bits/stdc++.h>
#define ent '\n'

using namespace std;
typedef long long ll;
const int maxn = 1e5 + 12;

int dp[maxn], a[maxn];
int p[20][maxn], lg[maxn];
int n, d;

struct segtree{
    int t[maxn * 4];
    segtree(){
        for(int i=0;i<maxn*4;i++){
            t[i] = 0;
        }
    }

    void upd(int v, int tl, int tr, int pos, int x){
        if(tl == tr){
            t[v] = x;
        }
        else{
            int mid = tl + tr >> 1;
            if(pos <= mid){
                upd(v*2, tl, mid, pos, x);
            }
            else{
                upd(v*2+1, mid+1, tr, pos, x);
            }
            t[v] = max(t[v*2], t[v*2+1]);
        }
    }

    int get(int v, int tl, int tr, int l, int r){
        if(tl > r || l > tr) return 0;
        if(tl >= l && tr <= r) return t[v];
        int mid = tl + tr >> 1;
        return max(get(v*2, tl, mid, l, r), get(v*2+1, mid+1, tr, l, r));
    }
} ft, st;

int get(int l, int r){
    if(l > r) return 0;
    int k = lg[r - l + 1];
    return max(p[k][l], p[k][r - (1 << k) + 1]);
}

void init(int N, std::vector<int> H) {
    n = N;
    for(int i=1;i<=n;i++){
        a[i] = p[0][i] = H[i - 1];
        if(i > 1) lg[i] = lg[i / 2] + 1;
    }
    for(int k=1;k<20;k++){
        for(int i=1;i + (1 << k) - 1 <= n;i++){
            p[k][i] = max(p[k-1][i], p[k-1][i + (1 << (k - 1))]);
        }
    }
}

int max_towers(int l, int r, int D) {
    d = D;
    l++, r++;

    vector<int> ord;
    for(int i=l;i<=r;i++){
        ord.push_back(i);
    }
    sort(ord.begin(), ord.end(), [](int i, int j){
        return a[i] < a[j];
    });
    set<int> s;
    for(int i:ord){
        auto it = s.upper_bound(i);
        bool ok = 1;
        ok &= (it == s.end() || get(i + 1, *it - 1) - d >= a[i]);
        if(s.size() && it != s.begin()){
            it--;
            ok &= (get(*it+1, i-1) - d >= a[i]);
        }
        if(ok) s.insert(i);
       else break;
    }
    return s.size();
}

Compilation message (stderr)

towers.cpp: In member function 'void segtree::upd(int, int, int, int, int)':
towers.cpp:26:26: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   26 |             int mid = tl + tr >> 1;
      |                       ~~~^~~~
towers.cpp: In member function 'int segtree::get(int, int, int, int, int)':
towers.cpp:40:22: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   40 |         int mid = tl + tr >> 1;
      |                   ~~~^~~~

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