HackerRank - "Stars"

Not hard, but with some amount of coding. Brutal-force would work: iterate each unique pair of points. And I used "y=ax+b" to check each point which side it resides.

import math

EPSI = 0.00000001

# y = ax + b
def calcAB(p0, p1):
if (p0[1] == p1[1]):
return 0, p0[1]
a = (p0[1] - p1[1])/(p0[0] - p1[0])
b = p0[1] - a * (p0[0])
return a, b

def splitPV(coords, ws, xs, wpp, ni, nj):
left = right = 0
for i in range(len(ws)):
if (i == ni or i == nj): continue
p = coords[i]
w = ws[i]
if (p[0] < xs):
left += w
elif (p[0] > xs):
right += w

if (left < right):
left += wpp
else:
right += wpp
return abs(left - right), min(left, right)

def splitP(coords, vs, ca, cb, wpp, ni, nj):
left = right = 0
for i in range(len(ws)):
if (i == ni or i == nj): continue
p = coords[i]
w = ws[i]
func_v = p[0] * ca + cb
if (func_v < p[1]):
left += w
elif (func_v > p[1]):
right += w

if (left < right):
left += wpp
else:
right += wpp
return abs(left - right), min(left, right)

# Get Input
coords = []
ws = []
n = int(input())
for _ in range(n):
x, y, w = map(int, input().split())
coords.append([x, y])
ws.append(w)

# Brutal Force
diff = 99999999999999
minw = 0
plen = len(ws)
for i in range(plen):
for j in range(i + 1, plen):
p0 = coords[i]
p1 = coords[j]
wpp = ws[i] + ws[j]

min_diff = minw = 0
# Case 1: vertical
if (abs(p0[0]-p1[0]) <= EPSI):
xs = p0[0]
min_diff, minw = splitPV(coords, ws, xs, wpp, i, j)
# Case 2: any other
else:
a, b = calcAB(p0, p1)
min_diff, minw = splitP(coords, ws, a, b, wpp, i, j)

if (min_diff < diff):
diff = min_diff
grp = minw

print (grp)