Submission #1036386

#	Time	Username	Problem	Language	Result	Execution time	Memory
1036386		AmirAli_H1	Aliens (IOI16_aliens)	C++17	0 / 100	21 ms	47328 KiB

aliens

// In the name of Allah
 
#include <bits/stdc++.h>
#include "aliens.h"
using namespace std;
 
typedef		long long int			ll;
typedef		long double				ld;
typedef		pair<int, int>			pii;
typedef		pair<ll, ll>			pll;
typedef		complex<ld>				cld;
 
#define		all(x)					(x).begin(),(x).end()
#define		len(x)					((ll) (x).size())
#define		F						first
#define		S						second
#define		pb						push_back
#define		sep						' '
#define		endl					'\n'
#define		Mp						make_pair
#define		kill(x)					cout << x << '\n', exit(0)
#define		set_dec(x)				cout << fixed << setprecision(x);
#define		file_io(x,y)			freopen(x, "r", stdin); freopen(y, "w", stdout);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
 
const int maxn = 1e5 + 4;
const int maxs = 2e6 + 4;
const ll oo = 1e12 + 4;
 
int n, m, k;
pii a[maxn]; vector<pii> A;
vector<int> ls[maxs];
priority_queue<pair<int, pii>> qu;
pll dp[maxn];
 
ll cal(pll a, pll b) {
	ll d = max(0ll, (a.F + a.S) - (b.F - b.S));
	return (4 * b.S * b.S - d * d);
}
 
pll get_val(int i, int j, ll R) {
	ll x1 = A[i + 1].F - A[i + 1].S, x2 = A[j].F + A[j].S;
	ll d = (x1 - x2) / 2; pll x = Mp(x1 + d, d);
	return Mp(dp[i].F + cal(A[i], x) + R, dp[i].S + 1);
}
 
pll get_res(ll R) {
	dp[0] = Mp(0, 0);
	for (int i = 1; i < n; i++) {
		dp[i] = get_val(0, i, R);
		for (int j = 1; j < i; j++) dp[i] = min(dp[i], get_val(j, i, R));
	}
	return dp[n - 1];
}
 
ll take_photos(int Nx, int Mx, int Kx, vector<int> rx, vector<int> cx) {
	n = Nx; m = Mx; k = Kx;
	for (int i = 0; i < n; i++) {
		if (cx[i] > rx[i]) swap(cx[i], rx[i]);
		a[i] = Mp(rx[i], cx[i]);
		ls[a[i].F].pb(i);
	}
	
	A.pb(Mp(0, 0));
	for (int i = m - 1; i >= 0; i--) {
		for (int j : ls[i]) {
			qu.push(Mp(-a[j].S, Mp(i, j)));
		}
		for (int j : ls[i]) {
			if (qu.top().S.S == j) {
				int x1 = a[j].F, y1 = a[j].S;
				A.pb(Mp(x1 + y1 + 1, x1 - y1 + 1));
			}
		}
	}
	n = len(A); sort(all(A));
	
	ll l = -oo, r = oo;
	while (r - l > 1) {
		ll mid = (l + r) / 2;
		if (get_res(mid).S >= k) l = mid;
		else r = mid;
	}
	
	pll R = get_res(l);
	ll ans = R.F - k * l;
	return ans / 4;
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 12
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40