Code360 powered by Coding Ninjas X Naukri.com. Code360 powered by Coding Ninjas X Naukri.com

Longest Subarray Zero Sum

Easy
0/40
Average time to solve is 15m
profile
Contributed by
160 upvotes
Asked in companies
Morgan StanleyGenpactGrab

Problem statement

Ninja loves playing with numbers. So his friend gives him an array on his birthday. The array consists of positive and negative integers. Now Ninja is interested in finding the length of the longest subarray whose sum is zero.

Detailed explanation ( Input/output format, Notes, Images )
Constraints:
1 <= T <= 10
1 <= N <= 10^4
-10^5 <= arr[i] <= 10^5

Time Limit: 1 sec
Sample Input 1:
2 
5
1 3 -1 4 -4
4
1 -1 2 -2 
Sample Output 1:
2
4 
Explanation for Sample Output 1:
In the first test case, the given array is (1, 3, -1, 4, -4). The sub-arrays we can create are (1), (3), (-1), (4), (-4), (1, 3), (3, -1), (-1, 4), (4, -4), (1, 3, -1), (3, -1, 4), (-1, 4, -4), (1, 3, -1, 4), (3, -1, 4, -4), (1, 3, -1, 4, -4). Out of them only (4, -4) is the sub array whose sum is zero.Length of this sub array is 2 and hence we return 2 as the final answer.

In the second test case, the given array is (1, -1, 2, -2). The sub-arrays we can create are (1), (-1), (2), (-2), (1, -1), (-1, 2), (2, -2), (1, -1, 2), (-1, 2, -2), (1, -1, 2, -2). Out of them sub arrays with zer sum are (1, -1), (2, -2), (1, -1, 2, -2). Out of them only (1, -1, 2, -2) has the longest length of 4. Hence we return 4 as the final answer.
Sample Input 2:
2 
3
4 -5 1
4
1 2 1 -2
Sample Output 2 :
3
0
Full screen
Console