Maximum consecutive numbers present in an array | Java program to find largest consecutive numbers present in arr [ ] . ; We insert all the array elements into unordered set . ; check each possible sequence from the start then update optimal length ; if current element is the starting element of a sequence ; Then check for next elements in the sequence ; increment the value of array element and repeat search in the set ; Update optimal length if this length is more . To get the length as it is incremented one by one ; Driver code
import java . util . * ; class GFG { static int findLongestConseqSubseq ( int arr [ ] , int n ) { HashSet < Integer > S = new HashSet < Integer > ( ) ; for ( int i = 0 ; i < n ; i ++ ) S . add ( arr [ i ] ) ; int ans = 0 ; for ( int i = 0 ; i < n ; i ++ ) { if ( S . contains ( arr [ i ] ) ) { int j = arr [ i ] ; while ( S . contains ( j ) ) j ++ ; ans = Math . max ( ans , j - arr [ i ] ) ; } } return ans ; } public static void main ( String [ ] args ) { int arr [ ] = { 1 , 94 , 93 , 1000 , 5 , 92 , 78 } ; int n = arr . length ; System . out . println ( findLongestConseqSubseq ( arr , n ) ) ; } }