842 B | 842 chars
import sys
from math import sqrt, pi, sin, factorial
inp = lambda : sys.stdin.readline()[:-1]
mii = lambda x = " " : [*map(int,inp().split(x))]
mfi = lambda x = " " : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
def dis(a):
return sqrt(a[0]*a[0] + a[1]*a[1])
def solve():
n = ii()
points = [mii() for _ in range(n)]
ans = 111111111111111111111111
for j in range(0, 2 ** n):
z = [0, 0]
k = bin(j)[2:]
k = "0" * (n - len(k)) + k
if k.count("1") != k.count("0"):
continue
for i in range(n):
if k[i] == '1':
z[0] += points[i][0]
z[1] += points[i][1]
else:
z[0] -= points[i][0]
z[1] -= points[i][1]
ans = min(ans, dis(z))
print(ans)
if __name__ == "__main__":
tc = ii()
for t in range(tc):
solve()