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# First Missing Positive

Difficulty: MEDIUM Contributed By
Dhruv Sharma
Avg. time to solve
18 min
Success Rate
84%

Problem Statement
Suggest Edit

#### For example, the input [3, 4, -1, 1] should give output 2 because it is the smallest positive number that is missing in the input array.

##### Input format:
``````The first line of input contains a single integer T, representing the number of test cases or queries to be run.
Then the T test cases follow.

The first line of each test case contains a positive integer N which represents the length of the array.

The second line of each test case contains N integers representing the elements of the array 'ARR'.
``````
##### Output Format :
``````For each test case, print a single integer denoting the minimum positive integer that is missing from the given input array.

Th output of each test case will be printed in a separate line.
``````
##### Note:
``````You do not need to print anything. It has already been taken care of. Just implement the given function.
``````
##### Constraint :
``````1 <= T <= 10
1 <= N <= 10^5
-10^5 <= ARR[i] <= 10^5

Time Limit: 1 sec
``````
##### Sample Input 1 :
``````1
5
3 2 -6 1 0
``````
##### Sample Output 1:
``````4
``````
##### Explanation for Input 1:
``````The first positive number is 1 and it is present in the array similarly 2 and 3 are also present in the array. 4 is missing from the array. Thus, the minimum positive integer that is missing is 4.
``````
##### Sample Input 2 :
``````1
5
0 1 2 3 4
``````
##### Sample Output 2:
``````5
``````   Console