Submission #675055

#	Time	Username	Problem	Language	Result	Execution time	Memory
675055		numberes	Aliens (IOI16_aliens)	C++17	100 / 100	206 ms	18020 KiB

aliens

/**
 * @date    2022-12-26 10:42:24
 * @author  numberes
 * 煮不在乎.RAmen!
 */
#include<bits/stdc++.h>
#include "aliens.h"
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define ll long long
using namespace std;
ll g[1000005];
int t[1000005],dq[1000005],dl,dr;
int n,m,k;
int l[1000005],r[1000005],p[1000005];
struct line{
	ll k,b;
}li[1000005];
long double itsect(int a,int b){
	return (long double)(li[b].b-li[a].b)/(li[a].k-li[b].k);
}
void calc(ll c){
	memset(g,0,sizeof(g));memset(t,0,sizeof(t));
	dl=dr=1;dq[1]=1;
	li[1].k=-2*(ll)(l[1]-1);
	li[1].b=g[1]+(ll)(l[1]-1)*(ll)(l[1]-1)+c;
	for(int i=2;i<=n+1;i++){
		while(dl+1<=dr && itsect(dq[dl],dq[dl+1])<r[i-1]) ++dl;
		g[i]=li[dq[dl]].k*r[i-1]+li[dq[dl]].b+(ll)r[i-1]*(ll)r[i-1];
		t[i]=t[dq[dl]]+1;
		li[i].k=-2*(ll)(l[i]-1);
		li[i].b=g[i]+(ll)(l[i]-1)*(ll)(l[i]-1)-(ll)max(0,r[i-1]-l[i]+1)*
		(ll)max(0,r[i-1]-l[i]+1)+c;
		while(dl+1<=dr && itsect(i,dq[dr])<itsect(dq[dr],dq[dr-1])) dr--;
		dq[++dr]=i;
	}
}
ll solve(){
	ll lb=-1,ub=2e12;
	while(lb+1<=ub-1){
		ll mid=(lb+ub)>>1;
		calc(mid);
		if(t[n+1]>k) lb=mid;
		else ub=mid;
	}
	calc(ub);
	return g[n+1]-k*ub;
}
ll take_photos(int _n,int _m,int _k,vector<int> _r,vector<int> _c){
	n=_n;m=_m;k=_k;
	for(int i=0;i<n;i++){
		int le=min(_r[i],_c[i]),ri=max(_r[i],_c[i]);
		p[i]=i;_r[i]=le;_c[i]=ri;
	}
	sort(p,p+n,[&](int a,int b){return (_r[a]!=_r[b]?_r[a]<_r[b]:_c[a]>_c[b]);});
	int tmp=0,mr=-1;
	for(int i=0;i<n;i++)
		if(_c[p[i]]>mr){
			l[++tmp]=_r[p[i]];
			r[tmp]=_c[p[i]];
			mr=_c[p[i]];
		}
	n=tmp;
	return solve();
}

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