Submission #3879

#	Time	Username	Problem	Language	Result	Execution time	Memory
3879		hyeonjae0310	Divide into triangle (kriii1_D)	C++98	0 / 1	0 ms	1240 KiB

D

#include <stdio.h>
#include <algorithm>
#include <vector>

using namespace std;

typedef struct POINT
{
	pair<long long, long long> point;
	int index;
}POINT;

POINT STD;

long long CCW(pair<long long, long long> a, pair<long long, long long> b, pair<long long, long long> c)
{
	return (a.first*b.second+b.first*c.second+c.first+a.second)-(a.second*b.first+b.second*c.first+c.second*a.first);
}

bool pair_compare(POINT a, POINT b)
{
	if(a.point.first != b.point.first)
	{
		return (a.point.first < b.point.first);
	}
	else
	{
		return (a.point.second < b.point.second);
	}
}

bool angle_compare(POINT a, POINT b)
{
	return (CCW(STD.point, a.point, b.point) > 0);
}

int main()
{
	vector<POINT> pt;
	int N;
	scanf("%d", &N);
	pt.resize(3*N);
	for(int i = 0 ; i < 3*N ; i++)
	{
		scanf("%lld %lld", &pt[i].point.first, &pt[i].point.second);
		pt[i].index = i+1;
	}
	while(pt.size())
	{
		sort(pt.begin(), pt.end(), pair_compare);
		STD = pt[0];
		sort(pt.begin()+1, pt.end(), angle_compare);
		for(int i = 0 ; i < 3 ; i++)
		{
			printf("%d", pt[i].index);
			if(i == 2)
			{
				printf("\n");
			}
			else
			{
				printf(" ");
			}
		}
		for(int i = 0 ; i < 3 ; i++)
		{
			pt.erase(pt.begin());
		}
	}
	return 0;
}

• Subtask 1: 0 / 1