oj.uz

Submission #1051269

# Submission time Handle Problem Language Result Execution time Memory
1051269 2024-08-10T02:47:14 Z vu28082007 Building Bridges (CEOI17_building) C++14
100 / 100
 36 ms 24148 KB 
#include <bits/stdc++.h>
using namespace std;
 #define taskname "mvu"
#define fi first
#define se second
#define pb push_back
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()
{
     if(fopen(taskname".inp","r"))
  {
    freopen(taskname".inp", "r", stdin);
    freopen(taskname".out", "w", stdout);
  }
  cin.tie(0)->sync_with_stdio(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 function 'int main()':
building.cpp:73:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |     freopen(taskname".inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
building.cpp:74:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |     freopen(taskname".out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
building.cpp: In member function 'll liChao::query(int, int, int)':
building.cpp:51:5: warning: control reaches end of non-void function [-Wreturn-type]
   51 |     }
      |     ^

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 18012 KB Output is correct
2 Correct 4 ms 18012 KB Output is correct
3 Correct 4 ms 18012 KB Output is correct
4 Correct 6 ms 18176 KB Output is correct
5 Correct 5 ms 18012 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 21592 KB Output is correct
2 Correct 32 ms 21596 KB Output is correct
3 Correct 30 ms 19892 KB Output is correct
4 Correct 29 ms 20828 KB Output is correct
5 Correct 28 ms 22488 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 18012 KB Output is correct
2 Correct 4 ms 18012 KB Output is correct
3 Correct 4 ms 18012 KB Output is correct
4 Correct 6 ms 18176 KB Output is correct
5 Correct 5 ms 18012 KB Output is correct
6 Correct 30 ms 21592 KB Output is correct
7 Correct 32 ms 21596 KB Output is correct
8 Correct 30 ms 19892 KB Output is correct
9 Correct 29 ms 20828 KB Output is correct
10 Correct 28 ms 22488 KB Output is correct
11 Correct 36 ms 21076 KB Output is correct
12 Correct 35 ms 22560 KB Output is correct
13 Correct 29 ms 21076 KB Output is correct
14 Correct 35 ms 21076 KB Output is correct
15 Correct 31 ms 20816 KB Output is correct
16 Correct 29 ms 24148 KB Output is correct
17 Correct 27 ms 20816 KB Output is correct
18 Correct 27 ms 20836 KB Output is correct