Submission #3923

#	Time	Username	Problem	Language	Result	Execution time	Memory
3923		hyeonjae0310	Divide into triangle (kriii1_D)	C++98	0 / 1	0 ms	1680 KiB

D

#include <iostream>
#include <algorithm>
#include <cmath>

using namespace std;
typedef struct point{
	int x;
	int y;
	int idx;
} point;
point a[300];

int compare(point p1, point p2)
{
	if(p1.x==p2.x) return (p1.y<p2.y);
	else return (p1.x<p2.x);
}

int ccw(point A, point B, point C)
{
	return (A.x * B.y + B.x * C.y + C.x * A.y) - (A.x * C.y + B.x * A.y + C.x * B.y);
}

bool compare2(point p1, point p2)
{
	if(0<ccw(a[0],p1,p2)) return true;
	else return false;
}
int main()
{
	int n,i;

	cin>>n;
	n=n*3;

	for(i=0;i<n;i++)
	{
		cin>>a[i].x>>a[i].y;
		a[i].idx=i+1;
	}
	for(i=0;i<n;i+=3)
	{
		sort(a+i,a+n,compare);
		sort(a+1+i,a+n,compare2);
		cout<<a[i].idx<<' '<<a[i+1].idx<<' '<<a[i+2].idx<<'\n';
	}
	
	return 0;
}

• Subtask 1: 0 / 1