First Missing Positive Solution - The Coding Shala
In this post, we will learn how to solve the First Missing Positive problem and will implement its solution in Java.
First Missing Positive Problem
First Missing Positive Java Solution
Space Complexity: O(1)
The steps are below to solve this problem:
Step 1: The first missing positive number will be in the range of 1 to N+1, where N is the length of the array. So Other than these numbers we can ignore, make this change in the array.
Step 2: Now we will take the array elements as the index(their original position), and at the numbers' original position will make the array element negative so later we can check this number is available in the array.
Step 3: now find the first non-negative number in the array that is our first missing positive number.
Step 4: if we couldn't find the non-negative number then return N+1.
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