# Kcc03 - editorial

DIFFICULTY:
EASY

PREREQUISITES:
Modulus Operator , Linear Search

PROBLEM:

`````` We have to find the maximum modulus of a pair of number from an array.
``````

Explanation:

``````1) Naive Approach:

We can compute the modulo function for every possible pair of elements in an array of size N with a complexity of O(N^2).

Pseudo Code :

maxmodulo=0;
for i in range 0 to n-1:
for j in range i+1 to n-1:
if max(i,j)%min(i,j)>maxmodulo :
maxmodulo=max(i,j)%min(i,j);
end if
end for
end for

Time Complexity : O(N^2)
But this approach will fail as N <= 10^6 and it will give a TLE (Time Limit Exceed) Error.

2) Optimized Approach :

One can easily compute the result by taking modulo operator over the second largest and the largest element of the array.

Result = Second_Largest_Element % Largest_Element

Time Complexity : O(N);
``````

Editorialist’s Solution:
Can be found here.

@abhi55 @srvptk I would like to report to @admin @vijju123 that for this external contest https://www.codechef.com/KCCT2018 third problem https://www.codechef.com/KCCT2018/problems/KCC03 is repeated ans was already available on codechef on https://www.codechef.com/IOPC2017/problems/IOPC17C and I hope organizers and codechef admin will look into this issue before awarding any prizes.