Given a list and two elements, x and y find the nearest occurrence index of element x from element y.
Input : test_list = [2, 4, 5, 7, 8, 6, 3, 8, 7, 2, 0, 9, 4, 9, 4], x = 4, y = 6
Output : 1
Explanation : 4 is found at 1, 12 and 14th index, 6 is at 5th index, nearest is 1st index.Input : test_list = [2, 4, 5, 7, 8, 6, 3, 8, 7, 2, 0, 9, 4, 9, 4], x = 7, y = 6
Output : 3
Explanation : 7 is found at 3rd and 8th index, 6 is at 5th index, nearest is 3rd index.
Method : Using list comprehension + loop + index()
In this, we find all indices of y using list comprehension, and then get index of x using index(), post that loop is used to get index difference, the nearest index is returned as result.
Python3
# Python3 code to demonstrate working of # Nearest occurrence of x from y in List # Using list comprehension + loop + index() # function to find index of nearest # occurance between two elements def nearestOccuranceIndex(test_list, x, y): # checking if both elements are present in list if x not in test_list or y not in test_list: return -1 # getting indices of x x_idx = [idx for idx in range(len(test_list)) if test_list[idx] == x] # getting y index y_idx = test_list.index(y) # getting min_dist index min_dist = 1000000 res = None for ele in x_idx: # checking for min ele, and updating index if abs(ele - y_idx) < min_dist: res = ele min_dist = abs(ele - y_idx) return res # initializing list input_list = [2, 4, 5, 7, 8, 6, 3, 8, 4, 2, 0, 9, 4, 9, 4] # printing original list print("The original list is : " + str(input_list)) # initializing x x = 4 # initializing y y = 6 # printing result print("Minimum distance index: ", nearestOccuranceIndex(input_list, x, y)) |
Output:
The original list is : [2, 4, 5, 7, 8, 6, 3, 8, 4, 2, 0, 9, 4, 9, 4]
Minimum distance index: 8
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