Submission #606933

#	Time	Username	Problem	Language	Result	Execution time	Memory
606933		pakhomovee	Building Bridges (CEOI17_building)	C++17	0 / 100	65 ms	66000 KiB

building

#include <iostream>
#include <vector>
#include <string>

using namespace std;

#define int long long
const int inf = 1e18;
const int maxn = 1e6 + 1;

struct line {
    int k, b;
    line() {}
    line(int k, int b): k(k), b(b) {}
    int get(int x) { return k * x + b; }
};

line tree[maxn * 4];

void init(line l) {
    fill(tree, tree + maxn * 4, l);
}

int get(int i, int l, int r, int x) {
    if (l + 1 == r) return tree[i].get(x);
    int m = (l + r) / 2;
    if (x < m) return min(tree[i].get(x), get(i * 2, l, m, x));
    return min(tree[i].get(x), get(i * 2 + 1, m, r, x));
}

void upd(int i, int l, int r, line ln) {
    int m = (l + r) / 2;
    bool lt = ln.get(l) < tree[i].get(l);
    bool md = ln.get(m) < tree[i].get(m);
    if (md) {
        swap(tree[i], ln);
    }
    if (l + 1 == r) return;
    if (lt != md) {
        upd(i * 2, l, m, ln);
    } else {
        upd(i * 2 + 1, m, r, ln);
    }
}

int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    vector<int> h(n);
    for (int& i : h) cin >> i;
    vector<int> w(n);
    for (int& i : w) cin >> i;
    vector<int> dp(n, inf);
    dp[0] = 0;
    vector<int> pref(n + 1, 0);
    for (int i = 1; i <= n; ++i) pref[i] = pref[i - 1] + w[i - 1];
    init(line(-2 * h[0], h[0] * h[0]));
    for (int i = 1; i < n; ++i) {
        dp[i] = get(1, 0, maxn, h[i]) + h[i] * h[i] + pref[i];
        upd(1, 0, maxn, line(-2 * h[i], dp[i] - pref[i + 1] + h[i] * h[i]));
    }
    cout << dp.back();
}

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