I’m getting WA can anyone tell me what I’m doing wrong or the test case which fails in this.

http://www.codechef.com/viewsolution/1742653

# CHEFHACK - WA

**cyberghost23**#1

**anton_lunyov**#2

Try this test:

4 0 4 2 12 2 1 9 24 0 1 9 12 2 8 2 18

The answer is 2.

While your answer is 12.

UPD.

The answer is 12.

While your answer is 2.

@cyberghost23 : In your submission , you are using Arrays.binarySearch() . However the length of the array of primes “p” is not exactly the number of primes till the range you have found them . You should store the number of primes which are valid entries in array of primes “p” . And then you should use the method Arrays.binarySearch(int [] array , int fromIndex , int endIndex , int value ) . Pass fromIndex = 0 and endIndex = number of valid prime entries in the array . If you do binary search on the whole array , there are some junk entries in the end of array , which make the results undefined as the array now may not be sorted due to junk entries and binary search will not be able to function properly .