Submission #71635

#	Time	Username	Problem	Language	Result	Execution time	Memory
71635		gnoor	Shortcut (IOI16_shortcut)	C++17	0 / 100	3 ms	524 KiB

shortcut

#include "shortcut.h"

#include <vector>
#include <algorithm>

using namespace std;

vector<long long> qs;
vector<int> d;

vector<int> posj; //sort by qs[j]+d[j]
vector<int> posi; //sort by qs[i]-d[i]

bool work(long long k,long long c) {
	long long lft=-1e18;
	long long rgt=1e18;
	long long top=1e18;
	long long bot=-1e18;
	
	int n=(int)qs.size();

	int _i=0;
	for (int _j=0;_j<n;_j++) {
		int j=posj[_j];
		while (_i<n&&qs[j]-qs[posi[_i]]+d[j]+d[posi[_i]]>k) {
			int i=posi[_i];
			lft=max(lft,(qs[i]+d[i])-(qs[j]-d[j])-k+c);
			rgt=min(rgt,(qs[i]-d[i])-(qs[j]+d[j])+k-c);
			top=min(top,(qs[i]-d[i])+(qs[j]-d[j])+k-c);
			bot=max(bot,(qs[i]+d[i])+(qs[j]+d[j])-k+c);
			_i++;
		}
	}

	if (lft>rgt||bot>top) return false;
	long long x,y;
	for (int i=0;i<n;i++) {
		for (int j=i+1;j<n;j++) {
			x=qs[i]-qs[j];
			y=qs[i]+qs[j];
			if (lft<=x&&x<=rgt&&bot<=y&&y<=top) return true;
		}
	}
	return false;
}

long long find_shortcut(int n, vector<int> l, vector<int> d, int c)
{
	qs.resize(n,0);
	for (int i=1;i<n;i++) {
		qs[i]=l[i-1];
		qs[i]+=qs[i-1];
	}
	::d=d;

	posj.resize(n,0);
	posi.resize(n,0);
	for (int i=0;i<n;i++) {
		posi[i]=i;
		posj[i]=i;
	}

	sort(posj.begin(),posj.end(),[&](const int &a, const int &b) {
			return qs[a]+d[a]<qs[b]+d[b];
			});
	sort(posi.begin(),posi.end(),[&](const int &a, const int &b) {
			return qs[a]-d[a]<qs[b]-d[b];
			});
	

	long long lo=0;
	long long hi=1e15;
	long long mid;
	while (lo<hi) {
		mid=(lo+hi)>>1;
		if (work(mid,c)) {
			hi=mid;
		} else {
			lo=mid+1;
		}
	}
	return lo;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 14
• Subtask 3: 0 / 8
• Subtask 4: 0 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3