Submission #969939

#	Time	Username	Problem	Language	Result	Execution time	Memory
969939		Lalic	Aliens (IOI16_aliens)	C++17	60 / 100	200 ms	11840 KiB

aliens

#include "aliens.h"
#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define allr(x) x.rbegin(), x.rend()
#define mp make_pair

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

const int MAXN = 5e4+10;
const int MOD = 1e9+7;
const int INF = 0x3f3f3f3f;
const ll LINF = 0x3f3f3f3f3f3f3f3f;

ll ant[MAXN], dp[MAXN];
vector<pll> arr;

void dacCalc(int l, int r, int p, int q){
	if(r<l) return;
	
	int mid=(l+r)>>1;
	
	int opt=-1;
	ll val=LINF;
	for(int i=p;i<=min(q, mid);i++){
		ll curr=ant[i-1]+(arr[mid].se-arr[i].fi+1ll)*(arr[mid].se-arr[i].fi+1ll);
		if(mid!=(int)arr.size()-1) 
			curr-=max(arr[mid].se-arr[mid+1].fi+1ll, 0ll)*(arr[mid].se-arr[mid+1].fi+1ll);
		
		if(curr<val){
			opt=i;
			val=curr;
		}
	}
	
	dp[mid]=val;
	dacCalc(l, mid-1, p, opt);
	dacCalc(mid+1, r, opt, q);
}

ll take_photos(int n, int m, int k, vector<int> r, vector<int> c) {
	vector<pll> proc;
	for(int i=0;i<n;i++)
		proc.pb({min(r[i], c[i]), max(r[i], c[i])});
		
	sort(all(proc), [&](pll a, pll b){ return (a.fi!=b.fi ? a.fi<b.fi : a.se>b.se); });
	
	arr.pb({-1, -1});
	ll last=-1;
	for(auto u : proc){
		if(u.se<=last) continue;
		arr.pb(u);
		last=u.se;
	}
	
	int lim=(int)arr.size()-1;
	
	for(int i=1;i<=lim;i++) dp[i]=1e13;
	for(int i=0;i<k;i++){
		for(int j=1;j<=lim;j++) ant[j]=dp[j];
		dacCalc(1, lim, 1, lim);
	}
	
	return dp[(int)arr.size()-1];
}

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