标签：tin ted add elements contain java length log com
Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example, Given [100, 4, 200, 1, 3, 2], The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4. Your algorithm should run in O(n) complexity.
考虑了多种方法, 还是得遍历, 不过可以借助hashSet
public class Solution {
public int longestConsecutive(int[] nums) {
HashSet<Integer> set = new HashSet<Integer>();
for (int i : nums) {
set.add(i);
}
int ans = 0;
for (int i : nums) {
if (set.contains(i - 1)) {
continue;
}
int temp = 0;
while (set.contains(i++)) {
temp++;
}
ans = Math.max(ans, temp);
}
return ans;
}
}
128. Longest Consecutive Sequence
标签：tin ted add elements contain java length log com
原文地址：http://www.cnblogs.com/apanda009/p/7242273.html
