Longest Consecutive Sequence

import java.util.HashMap;public class LongestConsecutiveSequence {public static void main(String args[]){int a[]={100, 4, 200, 1, 3, 2};System.out.println(longestConsecutive(a));}public static int longestConsecutive(int[] num) {HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();for (int i = 0; i < num.length; i++) {map.put(num[i], 1);}int max =0;int count;for(int i=0;i<num.length;i++){if(map.isEmpty()) break;if(map.containsKey(num[i])){count=map.get(num[i]);int temp=num[i];while(map.containsKey(++temp)){count++;map.remove(temp);}temp=num[i];while(map.containsKey(--temp)){count++;map.remove(temp);}max=Math.max(max, count);}}return max;}}