# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
582908 | 600Mihnea | Building Bridges (CEOI17_building) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
typedef long double ld;
typedef long long ll;
struct T {
ll a;
ll b;
};
const int N = (int) 1e5 + 7;
const ll INF = (ll) 1e18 + 7;
int n;
ll h[N];
ll sum[N];
ll dp[N];
T coef[N];
/**
T first
T second
T third
T ff, ss, tt
ff.a * x + ff.b = ss.a * x + ss.b
ff.b - ss.b = x * (ss.a - ff.a)
(ff.b - ss.b) / (ss.a - ff.a) < (ss.b - tt.b) / (tt.a - ss.a)
(ff.b - ss.b) * (tt.a - ss.a) < (ss.b - tt.b) * (ss.a - ff.a)
**/
signed main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n;
for (int i = 1; i <= n; i++) {
int x;
cin >> x;
h[i] = x;
}
for (int i = 1; i <= n; i++) {
int x;
cin >> x;
sum[i] = sum[i - 1] + x;
}
dp[1] = 0;
for (int i = 2; i <= n; i++) {
dp[i] = INF;
}
vector<T> all;
for (int r = 2; r <= n; r++) {
T line = {- 2 * h[r - 1], dp[r - 1] + h[r - 1] * h[r - 1] - sum[r - 1]};
all.push_back(p3);
ll x = h[r];
for (auto &ln : all) {
dp[r] = min(dp[r], ln.a * x + ln.b);
}
dp[r] += h[r] * h[r] + sum[r - 1];
}
cout << dp[n] << "\n";
}