https://leetcode.com/problems/longest-consecutive-sequence/description/
Given an unsorted array of integers, find the length of the longest consecutive elements sequence.
Your algorithm should run in O(n) complexity.
Example:
Input: [100, 4, 200, 1, 3, 2]
Output: 4
Explanation: The longest consecutive elements sequence is [1, 2, 3, 4]. Therefore its length is 4.题解：边界值坑死了。。。
class Solution {
public:
int longestConsecutive(vector<int>& nums) {
int n = nums.size();
if (n <= 1){
return n;
}
int ans = 1, l = 1;
sort(nums.begin(), nums.end());
for (int i = 0; i < n - 1; i++){
if (nums[i] == nums[i + 1] - 1){
l++;
}
else if (nums[i] == nums[i + 1]){
continue;
}
else {
l = 1;
}
ans = max(ans, l);
}
return ans;
}
};