How to find the missing number in an array in python?
Problem DefinitionFind the missing numbers in a given list or array using Python. Show
For example in the There are multiple ways to solve this problem using Python. In this article, we will cover the most straightforward ones. AlgorithmStep 1: Create an empty array for missing items Step 2: Loop over the elements within the range of the first and last element of the array Step 3: Compare the loop variable with the given array if the value is not present append it to the missing array Note: The array must be sorted for this to work.
Use Solution 1
Output: 2. Using List Comprehension
Output:
Using list comprehension we encapsulated the above solution in a single line. 3. Using Set()
Output:
Here we created a set object of having values within the range of initial and final values of the provided array then compared it with the provided array to retrieve the missing value. Instead of subtraction, we can also use the
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Approach 1 (Using Hashing):The idea behind the following approach is
Below is the implementation of the above approach: C++
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Time Complexity: O(N) Approach 2 (Using summation of first N natural numbers): The idea behind the approach is to use the summation of the first N numbers.
Follow the steps mentioned below to implement the idea:
Below is the implementation of the above approach: C++14
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Time Complexity: O(N) Modification for Overflow: The approach remains the same but there can be an overflow if N is large.
Algorithm:
Below is the implementation of the above approach: C++
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Time Complexity: O(N). Only one traversal of the array is needed. Approach 3 (Using binary operations): This method uses the technique of XOR to solve the problem.
Follow the steps mentioned below to implement the idea:
Below is the implementation of the above approach: C++
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Time Complexity: O(N) Approach 4 (UsingCyclic Sort): The idea behind it is as follows:
Follow the below steps to implement the idea:
Below is the implementation of the above approach. C++
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Time Complexity: O(N), requires (N-1) comparisons Approach 5 (Use elements as Index and mark the visited places as negative): Use the below idea to get the approach
Follow the steps to solve the problem:
Below is the implementation of the above approach: C++
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Time Complexity: O(N) How do you find the missing number in an array of numbers?Simple Approach. Calculate the summation of first N natural numbers as Total = N * (N + 1) / 2.. Create a variable sum to store the summation of elements of the array.. Iterate the array from start to end.. Updating the value of sum as sum = sum + array[i]. Print the missing number as the Total – sum.. How do you find missing elements in an array?Follow the steps mentioned below to implement the idea:. Calculate the sum of the first N natural numbers as sumtotal= N*(N+1)/2.. Traverse the array from start to end. Find the sum of all the array elements.. Print the missing number as SumTotal – sum of array.. How do you find the missing number in a Python sequence?Algorithm. Step 1: Create an empty array for missing items.. Step 2: Loop over the elements within the range of the first and last element of the array.. Step 3: Compare the loop variable with the given array if the value is not present append it to the missing array.. Note: The array must be sorted for this to work. ... . Output:. How do you find multiple missing numbers in an array in Python?To find the multiple missing elements run a loop inside it and see if the diff is less than arr[i] – i then print the missing element i.e., i + diff. Now increment the diff as the difference is increased now. Repeat from step 2 until all the missing numbers are not found.
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