oj.uz

Submission #1023146

# Submission time Handle Problem Language Result Execution time Memory
1023146 2024-07-14T11:05:40 Z _callmelucian Building Bridges (CEOI17_building) C++14
100 / 100
 47 ms 19576 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int,int> pii;
#define all(v) v.begin(), v.end()

struct line {
    ll a, b;

    line() : a(0), b() {}
    line (ll a, ll b) : a(a), b(b) {}

    ll calc (ll x) { return a * x + b; }

    ll slope() { return a; }
};

struct liChao {
    vector<line> tr;

    liChao() {}
    liChao (int sz) : tr(sz + 1, line(0, LLONG_MAX)) {}

    void update (line f, int l, int r) {
        if (l > r) return;
        int mid = (l + r) >> 1;
        if (l == r) {
            tr[mid] = (f.calc(l) < tr[mid].calc(l) ? f : tr[mid]);
            return;
        }
        if (f.slope() < tr[mid].slope()) swap(tr[mid], f);
        if (tr[mid].calc(mid) < f.calc(mid)) {
            update(f, l, mid - 1);
        }
        else {
            update(tr[mid], mid + 1, r);
            tr[mid] = f;
        }
    }

    ll query (int p, int l, int r) {
        int mid = (l + r) >> 1;
        ll cur = tr[mid].calc(p);
        if (p == mid) return cur;
        if (p < mid) return min(query(p, l, mid - 1), cur);
        if (p > mid) return min(query(p, mid + 1, r), cur);
    }
};

const int M = 1e6 + 1;
ll dp[M], h[M], w[M];

ll f1 (int k) {
    return -2 * h[k];
}

ll f2 (int k) {
    return dp[k] + h[k] * h[k] - w[k];
}

ll f3 (int k) {
    return h[k] * h[k] + w[k - 1];
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n; 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];
    }

    liChao tree(M);
    tree.update(line(f1(1), f2(1)), 0, M);

    for (int i = 2; i <= n; i++) {
        dp[i] = tree.query(h[i], 0, M) + f3(i);
        tree.update(line(f1(i), f2(i)), 0, M);
    }
    cout << dp[n];

    return 0;
}

Compilation message

building.cpp: In member function 'll liChao::query(int, int, int)':
building.cpp:48:5: warning: control reaches end of non-void function [-Wreturn-type]
   48 |     }
      |     ^

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 15964 KB Output is correct
2 Correct 6 ms 15964 KB Output is correct
3 Correct 6 ms 15964 KB Output is correct
4 Correct 7 ms 16172 KB Output is correct
5 Correct 7 ms 15964 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 43 ms 19292 KB Output is correct
2 Correct 39 ms 19344 KB Output is correct
3 Correct 42 ms 19284 KB Output is correct
4 Correct 37 ms 19280 KB Output is correct
5 Correct 36 ms 19284 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 15964 KB Output is correct
2 Correct 6 ms 15964 KB Output is correct
3 Correct 6 ms 15964 KB Output is correct
4 Correct 7 ms 16172 KB Output is correct
5 Correct 7 ms 15964 KB Output is correct
6 Correct 43 ms 19292 KB Output is correct
7 Correct 39 ms 19344 KB Output is correct
8 Correct 42 ms 19284 KB Output is correct
9 Correct 37 ms 19280 KB Output is correct
10 Correct 36 ms 19284 KB Output is correct
11 Correct 47 ms 19548 KB Output is correct
12 Correct 45 ms 19280 KB Output is correct
13 Correct 39 ms 19540 KB Output is correct
14 Correct 47 ms 19576 KB Output is correct
15 Correct 40 ms 19284 KB Output is correct
16 Correct 36 ms 19284 KB Output is correct
17 Correct 27 ms 19544 KB Output is correct
18 Correct 26 ms 19536 KB Output is correct