Largest Unique Number in Python

Suppose we have a list of numbers, we have to return the number whose occurrence is 1, if no such element is present, then return -1. So if the list is like [5,2,3,6,5,2,9,6,3], then the output will be 9.

To solve this, we will follow these steps −

• We will check each element, and put the elements inside the map, so if the element is not in map, then put a new entry, otherwise increase the value

• then go through the map, when the value is 1, return the key.

Example(Python)

Let us see the following implementation to get a better understanding −

 Live Demo

class Solution(object):    def largestUniqueNumber(self, A):       d = {}       ans = -1       for i in A:          if i not in d:             d[i]=1          else:             d[i] +=1       for a,b in d.items():          if b == 1:             ans = max(a,ans)       return ans ob1 = Solution() print(ob1.largestUniqueNumber([5,2,3,6,5,2,9,6,3]))

Input

[5,2,3,6,5,2,9,6,3]

Output

9