【刷題-LeetCode】300. Longest Increasing Subsequence
阿新 • • 發佈:2020-07-26
- Longest Increasing Subsequence
Given an unsorted array of integers, find the length of longest increasing subsequence.
Example:
Input: [10,9,2,5,3,7,101,18]
Output: 4
Explanation: The longest increasing subsequence is [2,3,7,101], therefore the length is 4.
Note:
- 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?
解 動態規劃[https://www.cnblogs.com/vinnson/p/10845125.html]
class Solution { public: int lengthOfLIS(vector<int>& nums) { int n = nums.size(); if(n == 0)return 0; int *dp = new int[n]; for(int i = 0; i < n; ++i)dp[i] = 1; int ans = 1; for(int i = 1; i < n; ++i){ for(int j = 0; j < i; ++j){ if(nums[i] > nums[j])dp[i] = max(dp[i], dp[j]+1); } ans = max(ans, dp[i]); } delete []dp; return ans; } };