通过生成二进制字符串的所有排列获得的唯一数字

给定一个二进制字符串S ，任务是打印所有不同的十进制数字，这些数字可以通过生成二进制字符串的所有排列来获得。

例子：

Input: S = “110”
Output: {3, 5, 6}
Explanation: 
All possible permutations are {“110”, “101”, “110”, “101”, “011”, “011”}.
Equivalent decimal numbers of these binary strings are {6, 5, 6, 5, 3, 3} respectively.
Therefore, the distinct decimal numbers obtained are {3, 5, 6}.

Input: S = “1010”
Output: {3, 5, 6, 9, 10, 12}

方法：可以使用Set解决问题。请按照以下步骤解决问题：

• 将给定的字符串转换为字符列表。
• 使用内置的Python函数itertools替换此列表。 permutations()。
• 初始化一个空字符串s。
• 遍历排列列表，并对每个排列执行以下步骤：
  • 遍历字符并将它们添加到字符串。
  • 将此二进制字符串转换为等效的小数。
  • 将获得的当前十进制值插入到集合中。
• 最后，打印出集合中存在的数字。

下面是上述方法的实现：

Python3

# Python3 program for the above approach
  
from itertools import permutations
  
# Function to convert binary
# string to equivalent decimal
def binToDec(n):
      
    num = n
    dec_value = 0
  
    # Initializing base
    # value to 1, i.e 2 ^ 0
    base1 = 1
  
    len1 = len(num)
      
    for i in range(len1 - 1, -1, -1):
          
        if (num[i] == '1'):
            dec_value += base1
          
        base1 = base1 * 2
  
    # Return the resultant
    # decimal number
    return dec_value
  
# Function to print all distinct
# decimals represented by the
# all permutations of the string
def printDecimal(permute):
      
    # Set to store distinct
    # decimal representations
    allDecimals = set()
      
    # Iterate over all permuations
    for i in permute:
          
        # Initilalize an empty string
        s = ""
          
        # Traverse the list
        for j in i:
            
            # Add each element
            # to the string
            s += j
              
        # Convert the current binary
        # representation to decimal
        result = binToDec(s)
          
        # Add the current decimal
        # value into the set
        allDecimals.add(result)
       
    # Print the distinct decimals   
    print(allDecimals)    
  
# Utility function to print all
# distinct decimal representations
# of all permutations of string
def totalPermutations(string):
    
    # Convert string to list
    lis = list(string)
      
    # Built in method to store all
    # the permuations of the list
    permutelist = permutations(lis)
      
    printDecimal(permutelist)
  
  
# Given binary  string
binarystring = '1010'
  
# Function call to print all distinct
# decimal values represented by all
# permutations of the given string
totalPermutations(binarystring)

输出：

{3, 5, 6, 9, 10, 12}

时间复杂度： O(N * N！)
辅助空间： O(N * N！)