Submission #388866

#	Time	Username	Problem	Language	Result	Execution time	Memory
388866		Keshi	Aliens (IOI16_aliens)	C++17	25 / 100	2071 ms	23500 KiB

aliens

//In the name of God
#include <bits/stdc++.h>
#include "aliens.h"
using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;

const ll maxn = 5e4 + 100;
const ll maxk = 105;
const ll mod = 1e9 + 7;
const ll inf = 1e18;

#define fast_io ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io freopen("input.txt", "r+", stdin);freopen("output.txt", "w+", stdout);
#define pb push_back
#define Mp make_pair
#define F first
#define S second
#define Sz(x) ll((x).size())
#define all(x) (x).begin(), (x).end()

vector<pll> vec;
ll ps[maxn];
vector<ll> dp[maxn];

void solve(ll k, ll l, ll r, ll s, ll e){
	if(l >= r) return;
	ll mid = (l + r) >> 1;
	ll opt = s;
	dp[k][mid] = inf;
	for(ll i = s; i < e && i <= mid; i++){
		ll x = dp[k - 1][i - 1] + (vec[mid].F - vec[i].S + 1) * (vec[mid].F - vec[i].S + 1) - ps[i];
		if(x < dp[k][mid]){
			dp[k][mid] = x;
			opt = i;
		}
	}
	solve(k, l, mid, s, e);
	solve(k, mid + 1, r, s, e);
	return;
}

long long take_photos(int n, int m, int k, vector<int> r, vector<int> c) {
	vector<pll> p(n);
	vec.pb(Mp(-1, -1));
	for(ll i = 0; i < n; i++){
		if(r[i] < c[i]) swap(r[i], c[i]);
		p[i] = Mp(c[i], -r[i]);
	}
	sort(all(p));
	ll mx = -1;
	for(ll i = 0; i < n; i++){
		p[i].S *= -1;
		if(p[i].S > mx){
			vec.pb(Mp(p[i].S, p[i].F));
			mx = p[i].S;
		}
	}
	n = Sz(vec) - 1;
	for(ll i = 2; i <= n; i++){
		ll x = max(0ll, vec[i - 1].F - vec[i].S + 1);
		ps[i] = x * x;
	}
	k = min(k, n);
	for(ll i = 0; i <= k; i++){
		dp[i].resize(n + 1, inf);
	}
	dp[0][0] = 0;
	for(ll i = 1; i <= k; i++){
		solve(i, 1, n + 1, 1, n + 1);
	}
    return dp[k][n];
}

/*int main(){
    fast_io;



    return 0;
}*/

Compilation message (stderr)

aliens.cpp: In function 'void solve(ll, ll, ll, ll, ll)':
aliens.cpp:30:5: warning: variable 'opt' set but not used [-Wunused-but-set-variable]
   30 |  ll opt = s;
      |     ^~~

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