[] 300. Longest Increasing Subsequence LeetCode rise longest sequence (Medium) (JAVA)
Topic Address: https://leetcode.com/problems/longest-increasing-subsequence/
Subject description:
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:
1. There may be more than one LIS combination, it is only necessary for you to return the length.
2. Your algorithm should run in O(n2) complexity.
Follow up: Could you improve it to O(n log n) time complexity?
Subject to the effect
A disorder of a given integer array, the length of the longest found rising sequence.
Problem-solving approach
1, to maintain an orderly queue List
2, replacing the corresponding positions in the ordered queue with a new element, if the element is larger than the last, is added to the ordered queue
class Solution {
public int lengthOfLIS(int[] nums) {
List<Integer> list = new ArrayList<>();
for (int i = 0; i < nums.length; i++) {
insert(list, nums[i]);
}
return list.size();
}
public void insert(List<Integer> list, int num) {
if (list.size() == 0 || list.get(list.size() - 1) < num) {
list.add(num);
return;
}
int start = 0;
int end = list.size() - 1;
while (start <= end) {
int mid = start + (end - start) / 2;
if (list.get(mid) == num) {
start = mid;
break;
} else if (list.get(mid) > num) {
end = mid - 1;
} else {
start = mid + 1;
}
}
list.set(start, num);
}
}
When execution: 1 ms, beat the 94.83% of all users to submit in Java
memory consumption: 37.7 MB, beat the 5.05% of all users to submit in Java
