Suppose we have a list of sorted list of distinct integers of size n, we have to find the first positive number in range [1 to n+1] that is not present in the array.
So, if the input is like nums = [0,5,1], then the output will be 2, as 2 is the first missing number in range 1 to 5.
To solve this, we will follow these steps −
target := 1
for each i in arr, do
if i is same as target, then
target := target + 1
Let us see the following implementation to get better understanding −
class Solution: def solve(self, arr): target = 1 for i in arr: if i == target: target += 1 return target ob = Solution() nums = [0,5,1] print(ob.solve(nums))