Python 中的 SymPy | Permutation.inversions()

原文:https://www . geesforgeks . org/sympy-排列-倒置-in-python/

arrangement . inversion():inversion()是一个 sympy Python 库函数,返回参数中置换的 inversion 个数值。 反转向量包括那些其值指示排列中的元素数量的元素,它们是<它并且位于它的右侧。

语法:返回:参数中排列的逆序数值

代码#1:反转()示例

# Python code explaining
# SymPy.Permutation.inversions()

# importing SymPy libraries
from sympy.combinatorics.partitions import Partition
from sympy.combinatorics.permutations import Permutation

# Using from 
# sympy.combinatorics.permutations.Permutation.inversions() method 

# creating Permutation
a = Permutation([[2, 0], [3, 1]])

b = Permutation([1, 3, 5, 4, 2, 0])

print ("Permutation a - inversions form : ", a.inversions())
print ("Permutation b - inversions form : ", b.inversions())

输出:

排列 a–倒排形式:4 排列 b–倒排形式:9

代码#2:反演()示例–2D 置换

# Python code explaining
# SymPy.Permutation.inversions()

# importing SymPy libraries
from sympy.combinatorics.partitions import Partition
from sympy.combinatorics.permutations import Permutation

# Using from sympy.combinatorics.permutations.Permutation.inversions() method 

# creating Permutation
a = Permutation([[2, 4, 0], 
                 [3, 1, 2],
                 [1, 5, 6]])

print ("Permutation a - inversions form : ", a.inversions())

输出:

排列 a–倒排形式:10