Submission #716406

#	Time	Username	Problem	Language	Result	Execution time	Memory
716406		Jarif_Rahman	Radio Towers (IOI22_towers)	C++17	0 / 100	4019 ms	4064 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> DL, DR, DLR;
vector<int> SL, SR;

void init(int _n, vector<int> _h){
    swap(n, _n);
    swap(h, _h);
    seg = segtree(n);
    DR.assign(n, 1e9);
    DL.assign(n, 1e9);
    DLR.assign(n, 1e9);
    SL.assign(n, 0);
    SR.resize(n, n-1);

    for(int i = 0; i < n; i++) seg.update(i, h[i]);

    stack<int> st;
    for(int i = n-1; i >= 0; i--){
        while(!st.empty() && h[i] < h[st.top()]){
            SL[st.top()] = i;
            DL[st.top()] = max(0, seg.get(i, st.top())-h[st.top()]);
            st.pop();
        }
        st.push(i);
    }
    while(!st.empty()) st.pop();
    for(int i = 0; i < n; i++){
        while(!st.empty() && h[i] < h[st.top()]){
            SR[st.top()] = i;
            DR[st.top()] = max(0, seg.get(st.top(), i)-h[st.top()]);
            st.pop();
        }
        st.push(i);
    }
    while(!st.empty()) st.pop();

    for(int i = 0;  i < n; i++) DLR[i] = min(DL[i], DR[i]);
}

int max_towers(int L, int R, int D){
    int ans = 0;
    int first = -1, last = -1;
    for(int i = L; i <= R; i++){
        if(D <= DLR[i]){
            ans++;
            if(first == -1) first = i;
            last = i;
        }
    }

    if(first == -1) return 1;

    for(int i = L; i < first; i++) if(D <= DR[i]){
        ans++;
        break;
    }
    for(int i = last+1; i <= R; i++) if(D <= DL[i]){
        ans++;
        break;
    }

    return ans;
}

• 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