Submission #716256

#	Time	Username	Problem	Language	Result	Execution time	Memory
716256		Jarif_Rahman	Radio Towers (IOI22_towers)	C++17	17 / 100	1075 ms	5044 KiB

towers

#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;

struct segtree{
    int k = 1;
    vector<int> v;
    segtree(int n){
        while(k < n) k*=2;
        v.assign(2*k, 0);
    }
    void update(int i, int x){
        i+=k;
        v[i] = x;
        i/=2;
        while(i){
            v[i] = max(v[2*i], v[2*i+1]);
            i/=2;
        }
    }
    int get(int l, int r, int nd, int a, int b){
        if(a > r || b < l) return 0;
        if(a >= l && b <= r) return v[nd];
        int md = (a+b)/2;
        return max(get(l, r, 2*nd, a, md), get(l, r, 2*nd+1, md+1, b));
    }
    int get(int l, int r){
        if(l > r) return 0;
        return get(l, r, 1, 0, k-1);
    }
};

int n;
vector<int> h;
segtree seg(0);
vector<int> o;
vector<int> diffs;

void init(int _n, vector<int> _h){
    swap(n, _n);
    swap(h, _h);
    seg = segtree(n);
    for(int i = 0; i < n; i++) seg.update(i, h[i]);
    for(int i = 0; i < n; i++) o.pb(i);
    sort(o.begin(), o.end(), [&](int a, int b){
        return h[a] < h[b];
    });

    set<int> s;
    for(int i: o){
        auto it = s.upper_bound(i);
        int x = 2e9;
        bool ok = 1;
        if(it != s.end()){
            int y = seg.get(i+1, *it-1);
            if(y < h[i]) ok = 0;
            x = min(x, y-h[i]);
        }
        if(it != s.begin()){
            int y = seg.get(*prev(it)+1, i-1);
            if(y < h[i]) ok = 0;
            x = min(x, y-h[i]);
        }
        if(ok) s.insert(i), diffs.pb(x);
    }

    sort(diffs.begin(), diffs.end());
}

int max_towers(int L, int R, int D){
    return int(diffs.size())-(lower_bound(diffs.begin(), diffs.end(), D)-diffs.begin());
}

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