Given an unsorted array of integers, find the length of longest increasing subsequence.
For example,
Given [10, 9, 2, 5, 3, 7, 101, 18]
,
The longest increasing subsequence is [2, 3, 7, 101]
, therefore the length is 4
. Note that there may be more than one LIS combination, it is only necessary for you to return the length.
Your algorithm should run in O(n2) complexity.
Follow up: Could you improve it to O(n log n) time complexity?
最长上升子序列。dp 二分。
dp[i]表示长度为i的序列最后一位是多少。
代码语言:javascript复制class Solution {
public:
int lengthOfLIS(vector<int>& nums) {
vector<int> res;
for(auto i : nums)
{
auto tmp = lower_bound(res.begin(), res.end(), i);
if(tmp == res.end()) res.push_back(i);
else *tmp = i;
}
return res.size();
}
};