#include "aliens.h"
#include <bits/stdc++.h>
using namespace std;
using i32 = int32_t;
#define int long long
struct Line {
int m, c;
int eval(int x) { return m * x + c; }
long double intersectX(Line l) { return (long double) (c - l.c) / (l.m - m); }
};
int take_photos(i32 n, i32 m, i32 K, std::vector<i32> r, std::vector<i32> c) {
vector<pair<int, int>> p;
for (int i = 0; i < n; i++) if (r[i] > c[i]) swap(r[i], c[i]);
for (int i = 0; i < n; i++) p.push_back({r[i], c[i]});
sort(p.begin(), p.end(), [] (auto x, auto y) {
if (x.first == y.first) return x.second > y.second;
return x.first < y.first;
});
int rmx = -1;
vector<int> L, R;
for (int i = 0; i < n; i++) {
if (rmx < p[i].second) {
L.push_back(p[i].first);
R.push_back(p[i].second);
rmx = p[i].second;
}
}
// deque<Line> q[K+1];
int N = L.size();
const int inf = 1e18;
auto solve_lambda = [&] (int c) {
// cout << c << '\n';
vector<pair<int, int>> dp(N);
deque<pair<Line, int>> q;
q.push_back({{-2 * (L[0] - 1), (L[0] - 1) * (L[0] - 1) + c}, 0}); // (r[i] - l[0] + 1) * (r[i] - l[0] + 1) = r[i]^2 - 2 * r[i] * (l[0] - 1) + (l[0] - 1) * (l[0] - 1);
for (int i = 0; i < N; i++) {
int pos = R[i];
while (q.size() >= 2 && q[0].first.eval(pos) > q[1].first.eval(pos)) q.pop_front();
if (!q.empty()) {
dp[i].first = q[0].first.eval(pos) + R[i] * R[i];
dp[i].second = q[0].second + 1;
}
if (i < N - 1) {
Line cur;
if (R[i] < L[i + 1]) cur = {-2 * (L[i+1] - 1), (L[i+1] - 1) * (L[i+1] - 1) + dp[i].first + c};
else cur = {-2 * (L[i+1] - 1), -R[i] * R[i] + 2 * (R[i]) * (L[i+1] - 1) + dp[i].first + c};
for (int k = q.size(); k >= 2 && q[k-2].first.intersectX(q[k-1].first) >= q[k-1].first.intersectX(cur); k--) q.pop_back();
q.push_back({cur, dp[i].second});
}
}
return dp[N - 1];
};
int lo = 0, hi = inf, ans = inf;
while (lo <= hi) {
int mid = (lo + hi) / 2;
pair<int, int> res = solve_lambda(mid);
if (res.second <= K) {
hi = mid - 1;
ans = mid;
}
else lo = mid + 1;
}
// cout << lo << " " << res.first << " " << res.second << '\n';
// for (int i = 0; i <= 5; i++) {
// pair<int, int> res = solve_lambda(i);
// cout << res.first << " " << res.second << '\n';
// }
pair<int, int> res = solve_lambda(ans);
return res.first - ans * K;
// cout << dp[K][N-1] << '\n';
// m = -2*(l[j+1] - 1)
// c = asdfasdfasdfasdf
// our query positions are increasing
// we want to find min
// m decreasing
// query positions increasing
// find minimum
// dp[i][k] = min(dp[j][k-1], (r[i] - l[j+1] + 1) * (r[i] - l[j+1] + 1) - (r[j] - l[j+1] + 1) * (r[j] - l[j+1] + 1));
// r[i]^2 - 2 * r[i] * (l[j+1] - 1) - r[j]^2 + 2 * (r[j]) * (l[j+1] - 1) // last part omit if r[j] < l[j+1]
}
Compilation message (stderr)
aliens.h:1:9: warning: #pragma once in main file
1 | #pragma once
| ^~~~
aliens_c.h:1:9: warning: #pragma once in main file
1 | #pragma once
| ^~~~
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