Python| SymPy Permutation.get_precedence_distance() 方法

Permutation.get_precedence_distance() ：get_precedence_distance()是一个 sympy Python库函数，用于计算两个排列之间的优先距离。

p 和 q 代表 n 个工作。优先级度量计数。在 p 和 q 中，作业 n 之前有作业 m 的次数。这是一个交换矩阵。

Syntax :
sympy.combinatorics.permutations.Permutation.get_precedence_distance()

Return :
precedence distance between two permutations

代码 #1：get_precedence_distance() 示例

# Python code explaining
# SymPy.Permutation.get_precedence_distance()
  
# importing SymPy libraries
from sympy.combinatorics.partitions import Partition
from sympy.combinatorics.permutations import Permutation
  
# Using from 
# sympy.combinatorics.permutations.Permutation.get_precedence_distance() method 
  
# creating Permutation
a = Permutation([2, 0, 3, 1, 5, 4])
  
b = Permutation([3, 1, 2, 5, 4, 0])
  
c = Permutation([0, 1, 3, 4, 5, 2])
  
print ("a - get_precedence_distance form b: ", a.get_precedence_distance(b))
print ("b - get_precedence_distance form c: ", b.get_precedence_distance(c))

输出 ：

a – get_precedence_distance form b: 6
b – get_precedence_distance form c: 9

代码 #2：get_precedence_distance() 示例– 2D 排列

# Python code explaining
# SymPy.Permutation.get_precedence_distance()
  
# importing SymPy libraries
from sympy.combinatorics.partitions import Partition
from sympy.combinatorics.permutations import Permutation
  
# Using from 
# sympy.combinatorics.permutations.Permutation.get_precedence_distance() method 
  
# creating Permutation
a = Permutation([[2, 4, 0], 
                 [7, 1, 3],
                 [8, 5, 6]])
  
b = Permutation([[8, 4, 0], 
                 [2, 7, 0],
                 [1, 6, 7]])
      
print ("a get_precedence_distance form b : ", a.get_precedence_distance(b))

输出 ：

a get_precedence_distance form b : 22