计算双向元组对的Python程序

给定元组列表，计算双向元组。

Input : test_list = [(5, 6), (1, 2), (6, 5), (9, 1), (6, 5), (2, 1)] 
Output : 3 
Explanation : (1, 2), (2, 1); (5, 6) -> [(6, 5), (6, 5)], total 3 pairs.

Input : test_list = [(5, 6), (1, 3), (6, 5), (9, 1), (6, 5), (2, 1)] 
Output : 2 
Explanation : (5, 6) -> [(6, 5), (6, 5)], total 2 pairs. 
 

方法：使用循环

在这里，我们检查每个元素是否有任何其他双向元素，一旦找到对，计数器就会增加。

Python3

# Python3 code to demonstrate working of
# Count Bidirectional Tuple Pairs
# Using loop
  
# initializing list
test_list = [(5, 6), (1, 2), (6, 5), (9, 1), (6, 5), (2, 1)]
  
# printing original list
print("The original list is : " + str(test_list))
  
res = 0
for idx in range(0, len(test_list)):
    for iidx in range(idx + 1, len(test_list)):
  
        # checking bidirection
        if test_list[iidx][0] == test_list[idx][1] and test_list[idx][1] == test_list[iidx][0]:
            res += 1
  
# printing result
print("Bidirectional pairs count : " + str(res))

输出：

The original list is : [(5, 6), (1, 2), (6, 5), (9, 1), (6, 5), (2, 1)]
Bidirectional pairs count : 3