Python | SymPy placement.descents()方法
原文:https://www.geesforgeks.org/python-sympy-置换-descents-method/
置换. descents() : descents() 是一个 sympy Python 库函数，返回置换中 descents 的位置。下降是 a[i] > a[i+1] 的元素
语法:sympy.combinations .排列.置换. descents()
返回:下降在排列中的位置
代码#1:下降()示例
# Python code explaining
# SymPy.descents()
# importing SymPy libraries
from sympy.combinatorics.partitions import Partition
from sympy.combinatorics.permutations import Permutation
# Using from sympy.combinatorics.permutations.Permutation.descents() method
# creating Permutation
a = Permutation([[2, 0], [3, 1]])
b = Permutation([1, 3, 5, 4, 2, 0])
print ("Permutation a - descents form : ", a.descents())
print ("Permutation b - descents form : ", b.descents())
输出:
排列 a–下降形式:[1] 排列 b–下降形式:[2，3，4]
代码#2:下降()示例–2D 排列
# Python code explaining
# SymPy.descents()
# importing SymPy libraries
from sympy.combinatorics.partitions import Partition
from sympy.combinatorics.permutations import Permutation
# Using from sympy.combinatorics.permutations.Permutation.descents() method
# creating Permutation
a = Permutation([[2, 4, 0],
[3, 1, 2],
[1, 5, 6]])
print ("Permutation a - descents form : ", a.descents())
输出:
排列 a–下降形式:[0，3，5]
