將函式改寫為 lambda 運算式

把以下三個以一般方式定義的函式，改寫成 lambda 運算式：

# Returns a bigger of the two numbers
def func1(x, y):
    if x >= y:
        return x

    return y

# Returns a dictionary counting characters in a string
def func2(s):
    d = dict()
    for c in set(s):
        d[c] = s.count(c)

    return d

# Returns a squared root of a sum of squared numbers
def func3(*nums):
    squared_nums = [n**2 for n in nums]
    sum_squared_nums = sum(squared_nums)

    return math.sqrt(sum_squared_nums)