Submission #389079

#	Time	Username	Problem	Language	Result	Execution time	Memory
389079		alishahali1382	Aliens (IOI16_aliens)	C++14	0 / 100	1 ms	460 KiB

aliens

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

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define debug(x) {cerr<<#x<<"="<<x<<"\n";}
#define debug2(x, y) {cerr<<#x<<", "<<#y<<" = "<<x<<", "<<y<<"\n";}
#define debugp(p) {cerr<<#p<<"={"<<p.first<<", "<<p.second<<"}\n";}
#define pb push_back
#define all(x) x.begin(), x.end()

const int inf=1000001000;
const ll INF=10000000010000000;
const int MAXN=100010, K=4010;

int n, m, k;
pii A[MAXN];
ll dp[2][K];

ll Inter(pll a, pll b){
	if (a.first==b.first) return (a.second<=b.second?-INF:INF);
	return (a.second-b.second)/(b.first-a.first) + ((a.second-b.second)%(b.first-a.first)>0);
}
struct CHT{
	// pair<ll, pll> A[MAXN];
	vector<pair<ll, pll>> A;
	int sz;
	inline void Add(pll x){
		while (sz && Inter(A[sz-1].second, x)<=A[sz-1].first) sz--;
		if (!sz) A[sz++]={-INF, x};
		else A[sz]={Inter(A[sz-1].second, x), x}, sz++;
	}
	inline ll Get(ll x){
		pll p=(upper_bound(all(A), make_pair(x, pll(INF, INF)))-1)->second;
		return p.first*x+p.second;
	}
} cht[K];

inline ll _sq(ll x){ return x*x;}
ll take_photos(int _n, int _m, int _k, vector<int> r, vector<int> c) {
	k=_k;
	m=_m;
	vector<pii> vec;
	for (int i=0; i<_n; i++) vec.pb({min(r[i], c[i]), max(r[i], c[i])});
	sort(all(vec), [](pii i, pii j){
		if (i.second!=j.second) return i.second<j.second;
		return i.first>j.first;
	});
	for (pii p:vec){
		while (n && p.first<=A[n].first) n--;
		A[++n]=p;
	}
	// for (int i=1; i<=n; i++) debugp(A[i])
	k=min(k, n);
	for (int i=0; i<k; i++) cht[i].A.resize(n+2);
	memset(dp, 63, sizeof(dp));
	for (int i=0; i<=k; i++) dp[0][i]=0;
	for (int i=1; i<=n; i++){
		int x=(i&1);
		for (int t=0; t<k; t++){
			ll val=_sq(A[i].first)+dp[x^1][t];
			if (i!=1 && A[i].first<=A[i-1].second) val-=_sq(A[i-1].second-A[i].first+1);
			cht[t].Add({A[i].first, -val});
		}
		dp[x][0]=INF;
		for (int t=1; t<=k; t++){
			dp[x][t]=_sq(A[i].second+1)-cht[t-1].Get(2*A[i].second+2);
		}
	}
	return dp[n&1][k];
}

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