Submission #2522975

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Source Code Expand

def tri(a,b,c):
	x = abs((a[0]-c[0])*(b[1]-c[1])-(b[0]-c[0])*(a[1]-c[1]))*1.0/2
	return x==int(x)
def tri2(a,b,c):
	if a[0]==b[0]==c[0]: return False
	elif a[0]==b[0] or a[0]==c[0]: return True
	elif (a[1]-b[1])*1.0/(a[0]-b[0])==(a[1]-c[1])*1.0/(a[0]-c[0]): return False
	else: return True
n = int(input())
x = [[int(i) for i in input().split()] for i in range(n)]
ans = 0
for i in range(n-2):
	for j in range(i+1,n-1):
		for k in range(j+1,n):
			if tri(x[i],x[j],x[k]) and tri2(x[i],x[j],x[k]): ans+=1
print(ans)

Submission Info

Judge Result