oj.uz

Submission #841818

# Submission time Handle Problem Language Result Execution time Memory
841818 2023-09-02T06:56:24 Z WLZ Building Bridges (CEOI17_building) C++17
100 / 100
 46 ms 10072 KB 
#include <bits/stdc++.h>
using namespace std;
 
using ll = long long;
 
struct Line {
	mutable ll k, m, p;
	bool operator<(const Line& o) const { return k < o.k; }
	bool operator<(ll x) const { return p < x; }
};
 
struct LineContainer : multiset<Line, less<>> {
	// (for doubles, use inf = 1/.0, div(a,b) = a/b)
	static const ll inf = LLONG_MAX;
	ll div(ll a, ll b) { // floored division
		return a / b - ((a ^ b) < 0 && a % b); }
	bool isect(iterator x, iterator y) {
		if (y == end()) return x->p = inf, 0;
		if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
		else x->p = div(y->m - x->m, x->k - y->k);
		return x->p >= y->p;
	}
	void add(ll k, ll m) {
		auto z = insert({k, m, 0}), y = z++, x = y;
		while (isect(y, z)) z = erase(z);
		if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
		while ((y = x) != begin() && (--x)->p >= y->p)
			isect(x, erase(y));
	}
	ll query(ll x) {
		assert(!empty());
		auto l = *lower_bound(x);
		return l.k * x + l.m;
	}
};
 
 
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  vector<long long> h(n + 1), w(n + 1, 0);
  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];
  vector<long long> dp(n + 1, 0);
  LineContainer cht;
  for (int i = 1; i <= n; i++) {
    if (i > 1) dp[i] = -cht.query(h[i]) + w[i - 1] + h[i] * h[i];
    cht.add(2ll * h[i], -(dp[i] - w[i] + h[i] * h[i]));
  }
  cout << dp[n] << '\n';
  return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 484 KB Output is correct
5 Correct 1 ms 348 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 33 ms 3796 KB Output is correct
2 Correct 37 ms 3824 KB Output is correct
3 Correct 34 ms 3676 KB Output is correct
4 Correct 28 ms 3676 KB Output is correct
5 Correct 26 ms 4956 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 484 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 33 ms 3796 KB Output is correct
7 Correct 37 ms 3824 KB Output is correct
8 Correct 34 ms 3676 KB Output is correct
9 Correct 28 ms 3676 KB Output is correct
10 Correct 26 ms 4956 KB Output is correct
11 Correct 29 ms 3932 KB Output is correct
12 Correct 32 ms 3864 KB Output is correct
13 Correct 25 ms 3932 KB Output is correct
14 Correct 32 ms 4188 KB Output is correct
15 Correct 46 ms 10072 KB Output is correct
16 Correct 26 ms 4692 KB Output is correct
17 Correct 16 ms 3676 KB Output is correct
18 Correct 16 ms 3888 KB Output is correct