제출 #571658

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
571658		piOOE	Building Bridges (CEOI17_building)	C++17	100 / 100	71 ms	7616 KiB

building

#include <bits/stdc++.h>

using namespace std;

#define sz(x) ((int)size(x))
#define all(x) begin(x), end(x)
#define trace(x) cout << #x << ": " << (x) << endl;

typedef long long ll;
typedef long double ld;
typedef double db;


mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

int rand(int l, int r) { return (int) ((ll) rnd() % (r - l + 1)) + l; }

template<typename T>
bool ckmn(T &x, T y) {
    if (x > y) {
        x = y;
        return true;
    }
    return false;
}

template<typename T>
bool ckmx(T &x, T y) {
    if (x < y) {
        x = y;
        return true;
    }
    return false;
}

const int N = 100001, infI = 1e9 + 7;
const ll infL = 3e18;

struct line {
    ll k = infI, b = infL;

    ll f(int x) {
        return k * x + b;
    }

    line() = default;

    line(ll a, ll bb) {
        k = a, b = bb;
    }
};

vector<line> t;
int sz = 1;
vector<int> X;

void add_line(line nw, int x = 1, int lx = 0, int rx = sz) {
    int mid = (lx + rx) >> 1;
    if (nw.f(X[mid]) < t[x].f(X[mid])) {
        swap(nw, t[x]);
    }
    if (lx + 1 == rx) {
        return;
    }
    if (t[x].k >= nw.k) {
        add_line(nw, x << 1 | 1, mid, rx);
    } else {
        add_line(nw, x << 1, lx, mid);
    }
}

ll get(int i) {
    int x = i + sz;
    ll ans = infL;
    while (x) {
        ans = min(ans, t[x].f(X[i]));
        x >>= 1;
    }
    return ans;
}

int h[N], w[N];

ll dp[N];

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    while (sz < n) {
        sz <<= 1;
    }
    t.resize(sz << 1);
    X.resize(sz);
    for (int i = 0; i < n; ++i) {
        cin >> h[i];
        X[i] = h[i];
    }

    for (int i = 0; i < n; ++i) {
        cin >> w[i];
    }
    sort(begin(X), begin(X) + n);
    for (int i = n; i < sz; ++i)
        X[i] = X[i - 1];
    dp[0] = 0;
    add_line({-2 * h[0], h[0] * (ll)h[0] - w[0]});
    ll sum = w[0];
    for (int i = 1; i < n; ++i) {
        dp[i] = get(lower_bound(all(X), h[i]) - begin(X)) + h[i] * (ll)h[i] + sum;
        sum += w[i];
        add_line({-2 * h[i], h[i] * (ll)h[i] + dp[i] - sum});
    }
    cout << dp[n - 1];
    return 0;
}

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