Submission #544717

#	Time	Username	Problem	Language	Result	Execution time	Memory
544717		JooDdae	Bulldozer (JOI17_bulldozer)	C++17	100 / 100	1144 ms	50036 KiB

bulldozer

#include <bits/stdc++.h>
using namespace std;
using ll = long long;

#define mid ((l+r) >> 1)

struct point{
    ll x, y, w;

    bool operator < (const point &o) const{
        return tie(x, y) < tie(o.x, o.y);
    }
};

struct line{
    int i, j;
    ll dx, dy;

    bool operator < (const line &o) const{
        return make_tuple(dy * o.dx, i, j) < make_tuple(o.dy * dx, o.i, o.j);
    }
    bool operator == (const line &o) const{
        return dy * o.dx == o.dy * dx;
    }
};

struct node{
    ll mx, l, r, s;

    node operator + (const node &o) const{
        return {max({mx, o.mx, r+o.l}), max(l, s+o.l), max(o.r, o.s+r), s+o.s};
    }
} t[8080];

int n;

void update(int id, ll w, int node = 1, int l = 1, int r = n){
    if(id < l || r < id) return;
    if(l == r){
        t[node] = {w, w, w, w};
        return;
    }
    update(id, w, node*2, l, mid), update(id, w, node*2+1, mid+1, r);
    t[node] = t[node*2] + t[node*2+1];
}

int main(){
    cin.tie(0)->sync_with_stdio(0);
    cin >> n;
    vector<point> v(n);
    for(auto &[x, y, w] : v) cin >> x >> y >> w;

    if(n == 1) return cout << max(0ll, v[0].w), 0;

    sort(v.begin(), v.end());
    vector<int> p(n); iota(p.begin(), p.end(), 0);
    for(int i=0;i<n;i++) update(i+1, v[i].w);

    vector<line> l;
    for(int i=0;i<n;i++) for(int j=i+1;j<n;j++) l.push_back({i, j, v[j].x-v[i].x, v[j].y-v[i].y});
    sort(l.begin(), l.end());
    int m = l.size();

    ll ans = 0;

     for(int i=0;i<m;i++){
        int j = i;
        while(j+1 < m && l[i] == l[j+1]) j++;

        for(int k=i;k<=j;k++){
            int a = l[k].i, b = l[k].j;
            swap(p[a], p[b]), swap(v[p[a]], v[p[b]]);
            update(p[a]+1, v[p[a]].w), update(p[b]+1, v[p[b]].w);
        }

        ans = max(ans, t[1].mx);

        i = j;
    }

    cout << ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 20 / 20
• Subtask 3: 35 / 35
• Subtask 4: 20 / 20
• Subtask 5: 20 / 20