Submission #1169869

#	Time	Username	Problem	Language	Result	Execution time	Memory
1169869		MinhKien	Building Bridges (CEOI17_building)	C++20	0 / 100	51 ms	65348 KiB

building

#include <iostream>

using namespace std;

#define ll long long
const int N = 1e5 + 10;
const int M = 1e6 + 10;
const ll INF = 1e18;

int n;
ll h[N], w[N], dp[N];

struct lichao {
    struct line {
        ll a, b;

        line() {a = b = INF;}
        line(ll A, ll B) {a = A, b = B;}
        ll calc(ll val) {return a == INF ? INF : a * val + b;}
        ll slope() {return a;}
    } st[M << 2];

    void update(int l, int r, line f, int id) {
        int m = (l + r) >> 1;

        if (st[id].calc(m) > f.calc(m)) swap(st[id], f);
        if (l == r) return;

        if (f.slope() < st[id].slope()) update(m + 1, r, f, id << 1);
        if (f.slope() > st[id].slope()) update(l, m, f, id << 1 | 1);
    }

    ll get(int l, int r, int u, int id) {
        ll cur = st[id].calc(u);
        if (l == r) return cur;
        int m = (l + r) >> 1;

        if (u <= m) return min(cur, get(l, m, u, id << 1));
        return min(cur, get(m + 1, r, u, id << 1 | 1));
    }
} Tree;

int main() {
    cin.tie(nullptr);
    cout.tie(nullptr);
    ios_base::sync_with_stdio(false);

    cin >> n;
    for (int i = 1; i <= n; ++i) cin >> h[i];
    for (int i = 1; i <= n; ++i) {
        cin >> w[i];
        w[i] += w[i - 1];
    }

    dp[1] = 0;
    Tree.update(0, 1e6, lichao::line(-2 * h[1], h[1] * h[1] - w[1]), 1);
    for (int i = 2; i <= n; ++i) {
        dp[i] = Tree.get(0, 1e6, h[i], 1) + h[i] * h[i] + w[i - 1];
        Tree.update(0, 1e6, lichao::line(-2 * h[i], h[i] * h[i] + dp[i] - w[i]), 1);
    }

    cout << dp[n] << "\n";

    return 0;
}

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40