Problem 2: Is Triangle... Right? (100pts)

Problem

Write a function that takes three integers (maybe non-positive) and returns True if the three integers can form the three sides of a right triangle, otherwise returns False.

编写一个函数，接受三个整数（可能包含非正数），如果这三个整数能构成直角三角形的三条边，则返回 True，否则返回 False。

def is_right_triangle(a, b, c):
    """Given three integers (maybe non-positive), judge whether the three
    integers can form the three sides of a right triangle.

    >>> is_right_triangle(2, 1, 3)
    False
    >>> is_right_triangle(5, -3, 4)
    False
    >>> is_right_triangle(5, 3, 4)
    True
    """
    "*** YOUR CODE HERE ***"

Hints

Hint1: A right triangle (in Euclidean space) is a triangle that has exactly one angle equal to 90 degrees.

Hint2: The three sides of a triangle cannot be negative or zero.

Hint3: If you are not familiar with right triangles, please refer to this page.

• 直角三角形（在欧几里得空间中）是指恰好有一个角等于 90 度的三角形。

• 三角形的三条边不能是负数或零。

• 如果您不熟悉直角三角形，请参考此页面。

• right triangle 不是“正确的三角形”！！！别看错题了

• 直角三角形的斜边最长，可以用 max 函数获取斜边长

Solutions

直接判断

def is_right_triangle(a, b, c):
    # 1. Sides must be positive
    if a <= 0 or b <= 0 or c <= 0:
        return False

    # 2. Check the Pythagorean theorem
    return (a**2 + b**2 == c**2 or 
            a**2 + c**2 == b**2 or 
            b**2 + c**2 == a**2)

---

用 max 函数获取斜边长

def is_right_triangle(a, b, c):
    # 1. Sides must be positive
    if a <= 0 or b <= 0 or c <= 0:
        return False

    # 2. Check the Pythagorean theorem
    return (a**2 + b**2 + c**2 - 2 * max(a, b, c)**2) == 0