oj.uz

Submission #919687

# Submission time Handle Problem Language Result Execution time Memory
919687 2024-02-01T12:40:06 Z penguin133 Building Bridges (CEOI17_building) C++17
100 / 100
 40 ms 10576 KB 
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define pi pair<int, int>
#define pii pair<int, pi>
#define fi first
#define se second
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
int n, H[100005], W[100005];
struct Line {
    mutable int k, m, p;
    bool operator<(const Line& o) const { return k < o.k; }
    bool operator<(int x) const { return p < x; }
};
struct LineContainer : multiset<Line, less<>> {
    // for doubles, use inf = 1/.0, div(a,b) = a / b
    static const int inf = 5e18;// implement this
    int div(int a, int 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(int k, int m) { // insert y = kx + 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));
    }
    int query(int x) { // max query
        assert(!empty());
        auto l = *lower_bound(x);
        return l.k * x + l.m;
    }
};
int dp[100005], P[100005];

void solve(){
	cin >> n;
	for(int i = 1; i <= n; i++)cin >> H[i];
	for(int i = 1; i <= n; i++)cin >> W[i], P[i] = P[i - 1] + W[i];
	dp[1] = 0;
	LineContainer hull;
	hull.add(2 * H[1], -(H[1] * H[1] - P[1]));
	for(int i = 2; i <= n; i++){
		dp[i] = -hull.query(H[i]) + H[i] * H[i] + P[i - 1];
		hull.add(2 * H[i], -(H[i] * H[i] - P[i] + dp[i]));
	}
	cout << dp[n];
}

main(){
	ios::sync_with_stdio(0);cin.tie(0);
	int tc = 1;
	//cin >> tc;
	for(int tc1=1;tc1<=tc;tc1++){
		// cout << "Case #" << tc1 << ": ";
		solve();
	}
}

Compilation message

building.cpp:60:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   60 | main(){
      | ^~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 1 ms 2396 KB Output is correct
4 Correct 1 ms 2396 KB Output is correct
5 Correct 1 ms 2392 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 31 ms 4440 KB Output is correct
2 Correct 34 ms 4440 KB Output is correct
3 Correct 33 ms 4440 KB Output is correct
4 Correct 28 ms 4524 KB Output is correct
5 Correct 26 ms 5452 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 1 ms 2396 KB Output is correct
4 Correct 1 ms 2396 KB Output is correct
5 Correct 1 ms 2392 KB Output is correct
6 Correct 31 ms 4440 KB Output is correct
7 Correct 34 ms 4440 KB Output is correct
8 Correct 33 ms 4440 KB Output is correct
9 Correct 28 ms 4524 KB Output is correct
10 Correct 26 ms 5452 KB Output is correct
11 Correct 29 ms 4696 KB Output is correct
12 Correct 31 ms 4656 KB Output is correct
13 Correct 24 ms 4688 KB Output is correct
14 Correct 31 ms 4952 KB Output is correct
15 Correct 40 ms 10576 KB Output is correct
16 Correct 26 ms 5468 KB Output is correct
17 Correct 17 ms 4444 KB Output is correct
18 Correct 18 ms 4696 KB Output is correct