Submission #1000867

#	Time	Username	Problem	Language	Result	Execution time	Memory
1000867		fryingduc	Salesman (IOI09_salesman)	C++17	60 / 100	444 ms	41556 KiB

salesman

#include "bits/stdc++.h"
using namespace std;

const int maxn = 5e5 + 5;
int n, d, u, s;
long long f[maxn];
const long long inf = 4e18;

struct info {
    int t, l, m;
    bool operator<(const info &o) {
        return t < o.t;
    }
} a[maxn];

struct segment_tree {
    int n;
    vector<long long> tree;
    segment_tree() {}
    segment_tree(int n) : n(n), tree(n * 4 + 6, -inf) {}
    void update(int ind, int l, int r, int pos, long long val) {
        if(l == r) {
            tree[ind] = max(tree[ind], val);
            return;
        }
        int mid = (l + r) / 2;
        if(pos <= mid) update(ind * 2, l, mid, pos, val);
        else update(ind * 2 + 1, mid + 1, r, pos, val);
        tree[ind] = max(tree[ind * 2], tree[ind * 2 + 1]);
    }
    long long get(int ind, int l, int r, int x, int y) {
        if(l > y || r < x) return -inf;
        if(x <= l and r <= y) return tree[ind];
        int mid = (l + r) / 2;
        return max(get(ind * 2, l, mid, x, y), get(ind * 2 + 1, mid + 1, r, x, y));
    }
    void update(int pos, long long val) {
        update(1, 1, n, pos, val);
    }
    long long get(int x, int y) {
        return get(1, 1, n, x, y);
    }
} up, down;
void solve() {
    cin >> n >> u >> d >> s;
    for(int i = 1; i <= n; ++i) {
        cin >> a[i].t >> a[i].l >> a[i].m;
    }
    up = segment_tree(maxn);
    down = segment_tree(maxn);
    
    sort(a + 1, a + n + 1);
    down.update(s, -(s * u));
    up.update(s, s * d);  
    
    long long ans = 0;
    
    for(int i = 1; i <= n; ++i) {
        long long cur_up = up.get(1, a[i].l - 1) - a[i].l * d + a[i].m; 
        long long cur_down = down.get(a[i].l + 1, maxn - 1) + a[i].l * u + a[i].m;
        
        f[i] = max(cur_up, cur_down);
        up.update(a[i].l, f[i] + 1ll * a[i].l * d);
        down.update(a[i].l, f[i] - 1ll * a[i].l * u);
        
        if(a[i].l >= s) {
            ans = max(ans, f[i] - 1ll * (a[i].l - s) * u);
        }
        else {
            ans = max(ans, f[i] - (s - a[i].l) * d);
        }
//        cerr << i << " " << f[i] << " " << cur_up << " " << cur_down << '\n';
    }
    cout << ans;
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    
    solve();
    return 0;
}

• Subtask 1: 60 / 100