Problem:
Distance For given two segments s1 and s2 , print the distance between them.  s1 is formed by end points p0 and p1 , and s2 is formed by end points p2 and p3 . Input The entire input looks like:  q (the number of queries)
1st query
2nd query
... q th query Each query consists of integer coordinates of end points of s1 and s2 in the following format:  x p0  y p0  x p1  y p1  x p2  y p2  x p3  y p3  Output For each query, print the distance. The output values should be in a decimal fraction with an error less than 0.00000001. Constraints  1 ≤ q ≤ 1000  -10000 ≤ x p i , y p i ≤ 10000   p0 ≠ p1 and p2 ≠ p3 .  Sample Input 3
0 0 1 0 0 1 1 1
0 0 1 0 2 1 1 2
-1 0 1 0 0 1 0 -1 Sample Output 1.0000000000
1.4142135624
0.0000000000

Solution (Python):
def dot(a, b):
  return a.real * b.real + a.imag * b.imag

def cross(a, b):
  return a.real * b.imag - a.imag * b.real

def ccw(p0, p1, p2):
  a = p1-p0
  b = p2-p0
  if cross(a,b) > 0:
    return 1 
  elif cross(a,b) <0:
    return -1 
  elif dot(a,b) < 0:
    return 2 
  elif abs(a) < abs(b):
    return -2 
  else:
    return 0 

def get_distanceLP(p0,p1,p2):
  return abs(cross(p1 - p0,p2-p0)/abs(p1-p0))

def get_distanceSP(p0,p1,p2):
  if dot(p1-p0,p2-p0)<0:
    return abs(p2-p0)
  if dot(p0-p1,p2-p1)<0:
    return abs(p2-p1)
  return get_distanceLP(p0,p1,p2)

def get_distance(a,b,c,d):
  if intersect(a,b,c,d):
    return 0
  return min(min(get_distanceSP(a,b,c),get_distanceSP(a,b,d)),min(get_distanceSP(c,d,a),get_distanceSP(c,d,b)))

def intersect(a,b,c,d):
  return ccw(a,b,c) * ccw(a,b,d) <=0 and ccw(c,d,a) * ccw(c,d,b) <=0

n=int(input())
for i in range(n):
  x0,y0,x1,y1,x2,y2,x3,y3 = map(int,input().split())
  p0=complex(x0,y0)
  p1=complex(x1,y1)
  p2=complex(x2,y2)
  p3=complex(x3,y3)
  print(get_distance(p0,p1,p2,p3))

Solution (Python):


from typing import List, Tuple
from math import sqrt

EPS = 1e-10


def float_equal(x: float, y: float) -> bool:
    return abs(x - y) < EPS


class Point:

    def __init__(self, x: float=0.0, y: float=0.0) -> None:
        self.x = x
        self.y = y

    def __repr__(self) -> str:
        return "Point({}, {})".format(self.x, self.y)

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Point):
            
            return NotImplemented
        return float_equal(self.x, other.x) and \
            float_equal(self.y, other.y)

    def __add__(self, other: 'Point') -> 'Point':
        return Point(self.x + other.x, self.y + other.y)

    def __sub__(self, other: 'Point') -> 'Point':
        return Point(self.x - other.x, self.y - other.y)

    def __mul__(self, k: float) -> 'Point':
        return Point(self.x * k, self.y * k)

    def __rmul__(self, k: float) -> 'Point':
        return self * k

    def __truediv__(self, k: float) -> 'Point':
        return Point(self.x / k, self.y / k)

    def __lt__(self, other: 'Point') -> bool:
        return self.y < other.y \
            if abs(self.x - other.x) < EPS \
            else self.x < other.x

    def norm(self):
        return self.x * self.x + self.y * self.y

    def abs(self):
        return sqrt(self.norm())

    def dot(self, other: 'Point') -> float:
        return self.x * other.x + self.y * other.y

    def cross(self, other: 'Point') -> float:
        return self.x * other.y - self.y * other.x

    def is_orthogonal(self, other: 'Point') -> bool:
        return float_equal(self.dot(other), 0.0)

    def is_parallel(self, other: 'Point') -> bool:
        return float_equal(self.cross(other), 0.0)

    def distance(self, other: 'Point') -> float:
        return Segment(self, other).vector().abs()

    def in_side_of(self, seg: 'Segment') -> bool:
        return seg.vector().dot(
            Segment(seg.p1, self).vector()) >= 0

    def in_width_of(self, seg: 'Segment') -> bool:
        return \
            self.in_side_of(seg) and \
            self.in_side_of(seg.reverse())

    def distance_to_segment(self, seg: 'Segment') -> float:
        if self.in_width_of(seg):
            return self.distance(seg.projection(self))
        else:
            return min(self.distance(seg.p1),
                       self.distance(seg.p2))


Vector = Point


class Segment:

    def __init__(self, p1: Point = None, p2: Point = None) -> None:
        self.p1: Point = Point() if p1 is None else p1
        self.p2: Point = Point() if p2 is None else p2

    def __repr__(self) -> str:
        return "Segment({}, {})".format(self.p1, self.p2)

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Segment):
            
            return NotImplemented
        return self.p1 == other.p1 and self.p2 == other.p2

    def vector(self) -> Vector:
        return self.p2 - self.p1

    def reverse(self) -> 'Segment':
        return Segment(self.p2, self.p1)

    def is_orthogonal(self, other: 'Segment') -> bool:
        return self.vector().is_orthogonal(other.vector())

    def is_parallel(self, other: 'Segment') -> bool:
        return self.vector().is_parallel(other.vector())

    def projection(self, p: Point) -> Point:
        v = self.vector()
        vp = p - self.p1
        return v.dot(vp) / v.norm() * v + self.p1

    def reflection(self, p: Point) -> Point:
        x = self.projection(p)
        return p + 2 * (x - p)

    def intersect_ratio(self, other: 'Segment') -> Tuple[float, float]:
        a = self.vector()
        b = other.vector()
        c = self.p1 - other.p1
        s = b.cross(c) / a.cross(b)
        t = a.cross(c) / a.cross(b)
        return s, t

    def intersects(self, other: 'Segment') -> bool:
        s, t = self.intersect_ratio(other)
        return (0 <= s <= 1) and (0 <= t <= 1)

    def intersection(self, other: 'Segment') -> Point:
        s, _ = self.intersect_ratio(other)
        return self.p1 + s * self.vector()

    def distance_with_segment(self, other: 'Segment') -> float:
        if not self.is_parallel(other) and \
                self.intersects(other):
            return 0
        else:
            return min(
                self.p1.distance_to_segment(other),
                self.p2.distance_to_segment(other),
                other.p1.distance_to_segment(self),
                other.p2.distance_to_segment(self))


Line = Segment


class Circle:

    def __init__(self, c: Point=None, r: float=0.0) -> None:
        self.c: Point = Point() if c is None else c
        self.r: float = r

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Circle):
            return NotImplemented
        return self.c == other.c and self.r == other.r

    def __repr__(self) -> str:
        return "Circle({}, {})".format(self.c, self.r)
        
def main() -> None:
    n = int(input())

    for _ in range(n):
        x1, y1, x2, y2, x3, y3, x4, y4 = [int(x) for x in input().split()]
        s1 = Segment(Point(x1, y1), Point(x2, y2))
        s2 = Segment(Point(x3, y3), Point(x4, y4))
        print(s1.distance_with_segment(s2))


if __name__ == "__main__":
    main()

Solution (Python):


from typing import List, Tuple
from math import sqrt

EPS = 1e-10


def float_equal(x: float, y: float) -> bool:
    return abs(x - y) < EPS


class Point:

    def __init__(self, x: float=0.0, y: float=0.0) -> None:
        self.x = x
        self.y = y

    def __repr__(self) -> str:
        return "Point({}, {})".format(self.x, self.y)

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Point):
            
            return NotImplemented
        return float_equal(self.x, other.x) and \
            float_equal(self.y, other.y)

    def __add__(self, other: 'Point') -> 'Point':
        return Point(self.x + other.x, self.y + other.y)

    def __sub__(self, other: 'Point') -> 'Point':
        return Point(self.x - other.x, self.y - other.y)

    def __mul__(self, k: float) -> 'Point':
        return Point(self.x * k, self.y * k)

    def __rmul__(self, k: float) -> 'Point':
        return self * k

    def __truediv__(self, k: float) -> 'Point':
        return Point(self.x / k, self.y / k)

    def __lt__(self, other: 'Point') -> bool:
        return self.y < other.y \
            if abs(self.x - other.x) < EPS \
            else self.x < other.x

    def norm(self):
        return self.x * self.x + self.y * self.y

    def abs(self):
        return sqrt(self.norm())

    def dot(self, other: 'Point') -> float:
        return self.x * other.x + self.y * other.y

    def cross(self, other: 'Point') -> float:
        return self.x * other.y - self.y * other.x

    def is_orthogonal(self, other: 'Point') -> bool:
        return float_equal(self.dot(other), 0.0)

    def is_parallel(self, other: 'Point') -> bool:
        return float_equal(self.cross(other), 0.0)

    def distance(self, other: 'Point') -> float:
        return (self - other).abs()

    def in_side_of(self, seg: 'Segment') -> bool:
        return seg.vector().dot(
            Segment(seg.p1, self).vector()) >= 0

    def in_width_of(self, seg: 'Segment') -> bool:
        return \
            self.in_side_of(seg) and \
            self.in_side_of(seg.reverse())

    def distance_to_segment(self, seg: 'Segment') -> float:
        if self.in_width_of(seg):
            return self.distance(seg.projection(self))
        else:
            return min(self.distance(seg.p1),
                       self.distance(seg.p2))


Vector = Point


class Segment:

    def __init__(self, p1: Point = None, p2: Point = None) -> None:
        self.p1: Point = Point() if p1 is None else p1
        self.p2: Point = Point() if p2 is None else p2

    def __repr__(self) -> str:
        return "Segment({}, {})".format(self.p1, self.p2)

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Segment):
            
            return NotImplemented
        return self.p1 == other.p1 and self.p2 == other.p2

    def vector(self) -> Vector:
        return self.p2 - self.p1

    def reverse(self) -> 'Segment':
        return Segment(self.p2, self.p1)

    def is_orthogonal(self, other: 'Segment') -> bool:
        return self.vector().is_orthogonal(other.vector())

    def is_parallel(self, other: 'Segment') -> bool:
        return self.vector().is_parallel(other.vector())

    def projection(self, p: Point) -> Point:
        v = self.vector()
        vp = p - self.p1
        return v.dot(vp) / v.norm() * v + self.p1

    def reflection(self, p: Point) -> Point:
        x = self.projection(p)
        return p + 2 * (x - p)

    def intersect_ratio(self, other: 'Segment') -> Tuple[float, float]:
        a = self.vector()
        b = other.vector()
        c = self.p1 - other.p1
        s = b.cross(c) / a.cross(b)
        t = a.cross(c) / a.cross(b)
        return s, t

    def intersects(self, other: 'Segment') -> bool:
        s, t = self.intersect_ratio(other)
        return (0 <= s <= 1) and (0 <= t <= 1)

    def intersection(self, other: 'Segment') -> Point:
        s, _ = self.intersect_ratio(other)
        return self.p1 + s * self.vector()

    def distance_with_segment(self, other: 'Segment') -> float:
        if not self.is_parallel(other) and \
                self.intersects(other):
            return 0
        else:
            return min(
                self.p1.distance_to_segment(other),
                self.p2.distance_to_segment(other),
                other.p1.distance_to_segment(self),
                other.p2.distance_to_segment(self))


Line = Segment


class Circle:

    def __init__(self, c: Point=None, r: float=0.0) -> None:
        self.c: Point = Point() if c is None else c
        self.r: float = r

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Circle):
            return NotImplemented
        return self.c == other.c and self.r == other.r

    def __repr__(self) -> str:
        return "Circle({}, {})".format(self.c, self.r)
        
def main() -> None:
    n = int(input())

    for _ in range(n):
        x1, y1, x2, y2, x3, y3, x4, y4 = [int(x) for x in input().split()]
        s1 = Segment(Point(x1, y1), Point(x2, y2))
        s2 = Segment(Point(x3, y3), Point(x4, y4))
        print(s1.distance_with_segment(s2))


if __name__ == "__main__":
    main()

Solution (Python):


from typing import List, Tuple
from math import sqrt

EPS = 1e-10


def float_equal(x: float, y: float) -> bool:
    return abs(x - y) < EPS


class Point:

    def __init__(self, x: float=0.0, y: float=0.0) -> None:
        self.x = x
        self.y = y

    def __repr__(self) -> str:
        return "Point({}, {})".format(self.x, self.y)

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Point):
            
            return NotImplemented
        return float_equal(self.x, other.x) and \
            float_equal(self.y, other.y)

    def __add__(self, other: 'Point') -> 'Point':
        return Point(self.x + other.x, self.y + other.y)

    def __sub__(self, other: 'Point') -> 'Point':
        return Point(self.x - other.x, self.y - other.y)

    def __mul__(self, k: float) -> 'Point':
        return Point(self.x * k, self.y * k)

    def __rmul__(self, k: float) -> 'Point':
        return self * k

    def __truediv__(self, k: float) -> 'Point':
        return Point(self.x / k, self.y / k)

    def __lt__(self, other: 'Point') -> bool:
        return self.y < other.y \
            if abs(self.x - other.x) < EPS \
            else self.x < other.x

    def norm(self):
        return self.x * self.x + self.y * self.y

    def abs(self):
        return sqrt(self.norm())

    def dot(self, other: 'Point') -> float:
        return self.x * other.x + self.y * other.y

    def cross(self, other: 'Point') -> float:
        return self.x * other.y - self.y * other.x

    def is_orthogonal(self, other: 'Point') -> bool:
        return float_equal(self.dot(other), 0.0)

    def is_parallel(self, other: 'Point') -> bool:
        return float_equal(self.cross(other), 0.0)

    def distance(self, other: 'Point') -> float:
        return (self - other).abs()

    def in_side_of(self, seg: 'Segment') -> bool:
        return seg.vector().dot(
            Segment(seg.p1, self).vector()) >= 0

    def in_width_of(self, seg: 'Segment') -> bool:
        return \
            self.in_side_of(seg) and \
            self.in_side_of(seg.reverse())

    def distance_to_segment(self, seg: 'Segment') -> float:
        if self.in_width_of(seg):
            return self.distance(seg.projection(self))
        else:
            return min(self.distance(seg.p1),
                       self.distance(seg.p2))


Vector = Point


class Segment:

    def __init__(self, p1: Point = None, p2: Point = None) -> None:
        self.p1: Point = Point() if p1 is None else p1
        self.p2: Point = Point() if p2 is None else p2

    def __repr__(self) -> str:
        return "Segment({}, {})".format(self.p1, self.p2)

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Segment):
            
            return NotImplemented
        return self.p1 == other.p1 and self.p2 == other.p2

    def vector(self) -> Vector:
        return self.p2 - self.p1

    def reverse(self) -> 'Segment':
        return Segment(self.p2, self.p1)

    def is_orthogonal(self, other: 'Segment') -> bool:
        return self.vector().is_orthogonal(other.vector())

    def is_parallel(self, other: 'Segment') -> bool:
        return self.vector().is_parallel(other.vector())

    def projection(self, p: Point) -> Point:
        v = self.vector()
        vp = p - self.p1
        return v.dot(vp) / v.norm() * v + self.p1

    def reflection(self, p: Point) -> Point:
        x = self.projection(p)
        return p + 2 * (x - p)

    def intersect_ratio(self, other: 'Segment') -> Tuple[float, float]:
        a = self.vector()
        b = other.vector()
        c = self.p1 - other.p1
        s = b.cross(c) / a.cross(b)
        t = a.cross(c) / a.cross(b)
        return s, t

    def intersects(self, other: 'Segment') -> bool:
        s, t = self.intersect_ratio(other)
        return (0 <= s <= 1) and (0 <= t <= 1)

    def intersection(self, other: 'Segment') -> Point:
        s, _ = self.intersect_ratio(other)
        return self.p1 + s * self.vector()

    def distance_with_segment(self, other: 'Segment') -> float:
        if not self.is_parallel(other) and \
                self.intersects(other):
            return 0
        else:
            return min(
                self.p1.distance_to_segment(other),
                self.p2.distance_to_segment(other),
                other.p1.distance_to_segment(self),
                other.p2.distance_to_segment(self))


Line = Segment


class Circle:

    def __init__(self, c: Point=None, r: float=0.0) -> None:
        self.c: Point = Point() if c is None else c
        self.r: float = r

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Circle):
            return NotImplemented
        return self.c == other.c and self.r == other.r

    def __repr__(self) -> str:
        return "Circle({}, {})".format(self.c, self.r)
        
def main() -> None:
    n = int(input())

    for _ in range(n):
        x1, y1, x2, y2, x3, y3, x4, y4 = [int(x) for x in input().split()]
        s1 = Segment(Point(x1, y1), Point(x2, y2))
        s2 = Segment(Point(x3, y3), Point(x4, y4))
        print(s1.distance_with_segment(s2))


if __name__ == "__main__":
    main()

Solution (Python):


from typing import List, Tuple
from math import sqrt

EPS = 1e-10


def float_equal(x: float, y: float) -> bool:
    return abs(x - y) < EPS


class Point:

    def __init__(self, x: float=0.0, y: float=0.0) -> None:
        self.x = x
        self.y = y

    def __repr__(self) -> str:
        return "Point({}, {})".format(self.x, self.y)

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Point):
            
            return NotImplemented
        return float_equal(self.x, other.x) and \
            float_equal(self.y, other.y)

    def __add__(self, other: 'Point') -> 'Point':
        return Point(self.x + other.x, self.y + other.y)

    def __sub__(self, other: 'Point') -> 'Point':
        return Point(self.x - other.x, self.y - other.y)

    def __mul__(self, k: float) -> 'Point':
        return Point(self.x * k, self.y * k)

    def __rmul__(self, k: float) -> 'Point':
        return self * k

    def __truediv__(self, k: float) -> 'Point':
        return Point(self.x / k, self.y / k)

    def __lt__(self, other: 'Point') -> bool:
        return self.y < other.y \
            if abs(self.x - other.x) < EPS \
            else self.x < other.x

    def norm(self):
        return self.x * self.x + self.y * self.y

    def abs(self):
        return sqrt(self.norm())

    def dot(self, other: 'Point') -> float:
        return self.x * other.x + self.y * other.y

    def cross(self, other: 'Point') -> float:
        return self.x * other.y - self.y * other.x

    def is_orthogonal(self, other: 'Point') -> bool:
        return float_equal(self.dot(other), 0.0)

    def is_parallel(self, other: 'Point') -> bool:
        return float_equal(self.cross(other), 0.0)

    def distance(self, other: 'Point') -> float:
        return (self - other).abs()

    def in_side_of(self, seg: 'Segment') -> bool:
        return seg.vector().dot(
            Segment(seg.p1, self).vector()) >= 0

    def in_width_of(self, seg: 'Segment') -> bool:
        return \
            self.in_side_of(seg) and \
            self.in_side_of(seg.reverse())

    def distance_to_line(self, seg: 'Segment') -> float:
        return \
            abs((self - seg.p1).cross(seg.vector())) / \
            seg.length()

    def distance_to_segment(self, seg: 'Segment') -> float:
        if not self.in_side_of(seg):
            return self.distance(seg.p1)
        if not self.in_side_of(seg.reverse()):
            return self.distance(seg.p2)
        else:
            return self.distance_to_line(seg)


Vector = Point


class Segment:

    def __init__(self, p1: Point = None, p2: Point = None) -> None:
        self.p1: Point = Point() if p1 is None else p1
        self.p2: Point = Point() if p2 is None else p2

    def __repr__(self) -> str:
        return "Segment({}, {})".format(self.p1, self.p2)

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Segment):
            
            return NotImplemented
        return self.p1 == other.p1 and self.p2 == other.p2

    def vector(self) -> Vector:
        return self.p2 - self.p1

    def reverse(self) -> 'Segment':
        return Segment(self.p2, self.p1)

    def length(self) -> float:
        return self.p1.distance(self.p2)

    def is_orthogonal(self, other: 'Segment') -> bool:
        return self.vector().is_orthogonal(other.vector())

    def is_parallel(self, other: 'Segment') -> bool:
        return self.vector().is_parallel(other.vector())

    def projection(self, p: Point) -> Point:
        v = self.vector()
        vp = p - self.p1
        return v.dot(vp) / v.norm() * v + self.p1

    def reflection(self, p: Point) -> Point:
        x = self.projection(p)
        return p + 2 * (x - p)

    def intersect_ratio(self, other: 'Segment') -> Tuple[float, float]:
        a = self.vector()
        b = other.vector()
        c = self.p1 - other.p1
        s = b.cross(c) / a.cross(b)
        t = a.cross(c) / a.cross(b)
        return s, t

    def intersects(self, other: 'Segment') -> bool:
        s, t = self.intersect_ratio(other)
        return (0 <= s <= 1) and (0 <= t <= 1)

    def intersection(self, other: 'Segment') -> Point:
        s, _ = self.intersect_ratio(other)
        return self.p1 + s * self.vector()

    def distance_with_segment(self, other: 'Segment') -> float:
        if not self.is_parallel(other) and \
                self.intersects(other):
            return 0
        else:
            return min(
                self.p1.distance_to_segment(other),
                self.p2.distance_to_segment(other),
                other.p1.distance_to_segment(self),
                other.p2.distance_to_segment(self))


Line = Segment


class Circle:

    def __init__(self, c: Point=None, r: float=0.0) -> None:
        self.c: Point = Point() if c is None else c
        self.r: float = r

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Circle):
            return NotImplemented
        return self.c == other.c and self.r == other.r

    def __repr__(self) -> str:
        return "Circle({}, {})".format(self.c, self.r)
       
def main() -> None:
    n = int(input())

    for _ in range(n):
        x1, y1, x2, y2, x3, y3, x4, y4 = [int(x) for x in input().split()]
        s1 = Segment(Point(x1, y1), Point(x2, y2))
        s2 = Segment(Point(x3, y3), Point(x4, y4))
        print(s1.distance_with_segment(s2))


if __name__ == "__main__":
    main()

Solution (Python):
from sys import stdin
import math

EPS = 1e-10

class Vector:
    def __init__(self, x=None, y=None):
        self.x = x
        self.y = y

    def __add__(self, other):
        return Vector(self.x + other.x, self.y + other.y)

    def __sub__(self, other):
        return Vector(self.x - other.x, self.y - other.y)

    def __mul__(self, k):
        return Vector(self.x * k, self.y * k)

    def __gt__(self, other):
        return self.x > other.x and self.y > other.yb

    def __lt__(self, other):
        return self.x < other.x and self.y < other.yb

    def __eq__(self, other):
        return self.x == other.x and self.y == other.y

    def dot(self, other):
        return self.x * other.x + self.y * other.y

    
    def cross(self, other):
        return self.x * other.y - self.y * other.x

    def norm(self):
        return self.x * self.x + self.y * self.y

    def abs(self):
        return math.sqrt(self.norm())

class Point(Vector):
    def __init__(self, *args, **kargs):
        return super().__init__(*args, **kargs)

class Segment:
    def __init__(self, p1=Point(0, 0), p2=Point(1, 1)):
        self.p1 = p1
        self.p2 = p2

def ccw(p0, p1, p2):
    a = p1 - p0
    b = p2 - p0
    if a.cross(b) > EPS:
        return 1
    elif a.cross(b) < -EPS:
        return -1
    elif a.dot(b) < -EPS:
        return 2
    elif a.norm() < b.norm():
        return -2
    else:
        return 0

def intersect(*args, **kwargs):
    
    if len(args) == 2:
        s1, s2 = args
        return (ccw(s1.p1, s1.p2, s2.p1) * ccw(s1.p1, s1.p2, s2.p2) <= 0 and
                    ccw(s2.p1, s2.p2, s1.p1) * ccw(s2.p1, s2.p2, s1.p2) <= 0)
    
    elif len(args) == 4:
        p0, p1, p2, p3 = args
        return (ccw(p0, p1, p2) * ccw(p0, p1, p3) <= 0 and
                    ccw(p2, p3, p0) * ccw(p2, p3, p1) <= 0)
    else:
        raise ArgsError

def get_distance_lp(l, p):
    v1 = l.p1 - l.p2
    v2 = p - l.p1
    return abs(v1.cross(v2))/v1.abs()

def get_distance_sp(s, p):
    v1 = s.p2 - s.p1
    v2 = p - s.p1
    v3 = s.p1 - s.p2
    v4 = p - s.p2
    if v1.dot(v2) < 0:
        return v2.abs()
    elif v3.dot(v4) < 0:
        return v4.abs()
    else:
        return get_distance_lp(s, p)

def get_distance(*args, **kwargs):
    
    if len(args) == 2:
        p1, p2 = args
        v = p1 - p2
        return v.abs()
    
    elif len(kwargs) == 2:
        s1 = kwargs['s1']
        s2 = kwargs['s2']
        if intersect(s1, s2):
            return 0.0
        else:
            return min(min(get_distance_sp(s1, s2.p1), get_distance_sp(s1, s2.p2)),
                        min(get_distance_sp(s2, s1.p1), get_distance_sp(s2, s1.p2)))
    else:
        raise ArgsError

def read_and_print_results(n):
    for _ in range(n):
        line = stdin.readline().strip().split()
        p0 = Vector(int(line[0]), int(line[1]))
        p1 = Vector(int(line[2]), int(line[3]))
        p2 = Vector(int(line[4]), int(line[5]))
        p3 = Vector(int(line[6]), int(line[7]))
        s1 = Segment(p0, p1)
        s2 = Segment(p2, p3)
        d = get_distance(s1=s1, s2=s2)
        print("{0:0.10f}".format(d))

n = int(input())
read_and_print_results(n)

Solution (Python):
from sys import stdin
readline = stdin.readline



def main():
    q = int(readline())
    for i in range(q):
        xy = map(int, readline().split())
        p0, p1, p2, p3 = [x + y * 1j for x, y in zip(*[xy] * 2)]
        print('{:.10f}'.format(distance(p0, p1, p2, p3)))

def lt(a, b):
    if a.real != b.real:
        return a.real <= b.real
    return a.imag < b.imag
import itertools
def distance(p0, p1, p2, p3):
    if is_intersected_ls(p0, p1, p2, p3):
        return 0
    p = []
    for i, j in itertools.product([p0, p1], [p2, p3]):
        p.append(abs(i - j))
    for i,j,k in [(p0,p1,p2),(p0,p1,p3),(p2,p3,p0),(p2,p3,p1)]:
        tmp = intersection_of_perpendicular(i,j,k)
        if (lt(i, tmp) and lt(tmp, j)) or (lt(j, tmp) and lt(tmp, i)):
            p.append(abs(tmp - k))

    return min(p)


def intersection_of_perpendicular(p1, p2, p3):
    return p1 + (p2 - p1) * projecter(p2 - p1, p3 - p1)
 
 
def projecter(a, b):
    return dot(a, b) / dot(a, a)
 
 
def dot(a, b):
    return a.real * b.real + a.imag * b.imag


def is_intersected_ls(a1, a2, b1, b2):
    eps = 0
    if max(a1.real, a2.real) < min(b1.real, b2.real)\
      or max(b1.real, b2.real) < min(a1.real, a2.real)\
      or max(a1.imag, a2.imag) < min(b1.imag, b2.imag)\
      or max(b1.imag, b2.imag) < min(a1.imag, a2.imag):
        return False
    return (cross(a2-a1, b1-a1) * cross(a2-a1, b2-a1) <= eps)\
        and (cross(b2-b1, a1-b1) * cross(b2-b1, a2-b1) <= eps)


def intersection(p1, p2, p3, p4):
    a1 = p4 - p2
    b1 = p2 - p3
    b2 = p1 - p2
    s1 = cross(a1, b2) / 2
    s2 = cross(a1, b1) / 2
    c1 = p1 + (p3 - p1) * s1 / (s1 + s2)
    return c1


def cross(a, b):
    return a.real * b.imag - a.imag * b.real
main()

Solution (Python):
from itertools import starmap


def cross(a, b):
    return a.real * b.imag - a.imag * b.real


def has_intersection(p0, p1, p2, p3):
    max_x1, min_x1 = (p0.real, p1.real) if p0.real > p1.real else (p1.real, p0.real)
    max_x2, min_x2 = (p2.real, p3.real) if p2.real > p3.real else (p3.real, p2.real)
    if max_x1 < min_x2 or max_x2 < min_x1:
        return False
    max_y1, min_y1 = (p0.imag, p1.imag) if p0.imag > p1.imag else (p1.imag, p0.imag)
    max_y2, min_y2 = (p2.imag, p3.imag) if p2.imag > p3.imag else (p3.imag, p2.imag)
    if max_y1 < min_y2 or max_y2 < min_y1:
        return False

    return cross(p1 - p0, p2 - p0) * cross(p1 - p0, p3 - p0) < 1e-6 and \
           cross(p3 - p2, p0 - p2) * cross(p3 - p2, p1 - p2) < 1e-6


def point_to_segment(p0, p1, p2):
    prod = (p1 - p0).conjugate() * (p2 - p0)
    if prod.real <= 1e-6:
        return abs(p2 - p0)
    l = abs(p1 - p0)
    d = prod.real / l
    if d >= l:
        return abs(p2 - p1)
    return abs(prod.imag) / l


q = int(input())
while q:
    q -= 1
    p0, p1, p2, p3 = starmap(complex, zip(*[map(int, input().split())] * 2))
    if has_intersection(p0, p1, p2, p3):
        print(0)
        continue

    print(min(starmap(point_to_segment, ((p0, p1, p2), (p0, p1, p3), (p2, p3, p0), (p2, p3, p1)))))

Solution (Python):
from math import sqrt
for t in xrange(input()):
    x0, y0, x1, y1, x2, y2, x3, y3 = map(int, raw_input().split())
    dx0 = x1 - x0
    dy0 = y1 - y0
    dx1 = x3 - x2
    dy1 = y3 - y2

    s = (y0-y2)*dx1 - (x0-x2)*dy1
    sm = dx0*dy1 - dy0*dx1
    if s < 0:
        s = -s
        sm = -sm
    t = (y2-y0)*dx0 - (x2-x0)*dy0
    tm = dx1*dy0 - dy1*dx0
    intersection = 0
    if t < 0:
        t = -t
        tm = -tm
    dis = sqrt(
            min(
                (x2-x0)**2 + (y2-y0)**2,
                (x3-x0)**2 + (y3-y0)**2,
                (x2-x1)**2 + (y2-y1)**2,
                (x3-x1)**2 + (y3-y1)**2
                )
            )
    ov = dx0*dy1 - dy0*dx1
    if 0 <= s <= max(sm, 0) and 0 <= t <= max(tm, 0):
        if ov == 0:
            r0 = dx0**2 + dy0**2
            r1 = (x2-x0)*dx0 + (y2-y0)*dy0
            r2 = (x3-x0)*dx0 + (y3-y0)*dy0
            if r1 > r2: r1, r2 = r2, r1
            if r2 < 0 or r0 < r1:
                intersection = 0
            else:
                intersection = 1
        else:
            intersection = 1
    else:
        if ov == 0:
            r0 = dx0**2 + dy0**2
            r1 = dx0*(x2-x0) + dy0*(y2-y0)
            r2 = dx0*(x3-x0) + dy0*(y3-y0)
            if 0 <= r2 and r1 <= r0:
                dis = min(dis, abs(dx0*(y2-y0) - dy0*(x2-x0)) / sqrt(r0))
        else:
            r0 = dx0**2 + dy0**2
            r1 = dx0*(x2-x0) + dy0*(y2-y0)
            r2 = dx0*(x3-x0) + dy0*(y3-y0)
            if 0 <= r1 <= r0:
                o1 = abs(dx0*(y2-y0) - dy0*(x2-x0))
                dis = min(dis, o1 / sqrt(r0))
            if 0 <= r2 <= r0:
                o2 = abs(dx0*(y3-y0) - dy0*(x3-x0))
                dis = min(dis, o2 / sqrt(r0))
            s0 = dx1**2 + dy1**2
            s1 = dx1*(x0-x2) + dy1*(y0-y2)
            s2 = dx1*(x1-x2) + dy1*(y1-y2)
            if 0 <= s1 <= s0:
                o1 = abs(dx1*(y0-y2) - dy1*(x0-x2))
                dis = min(dis, o1 / sqrt(s0))
            if 0 <= s2 <= s0:
                o2 = abs(dx1*(y1-y2) - dy1*(x1-x2))
                dis = min(dis, o2 / sqrt(s0))

        intersection = 0
    if intersection:
        print "%.09f" % 0
    else:
        print "%.09f" % dis