Longest Increasing Subsequence LeetCode Solution

Last updated on July 19th, 2024 at 10:22 pm

Here, We see Longest Increasing Subsequence LeetCode Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc. with different approaches.

List of all LeetCode Solution

Topics

Binary Search, Dynamic Programming

Companies

Microsoft

Level of Question

Medium

Longest Increasing Subsequence LeetCode Solution

Longest Increasing Subsequence LeetCode Solution

Problem Statement

Given an integer array nums, return the length of the longest strictly increasing subsequence.

Example 1:
Input: nums = [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.

Example 2:
Input: nums = [0,1,0,3,2,3]
Output: 4

Example 3:
Input: nums = [7,7,7,7,7,7,7]
Output: 1

1. Longest Increasing Subsequence Leetcode Solution C++

class Solution {
public:
    int lengthOfLIS(vector<int>& nums) {
        vector<int> res;
        for(int i=0; i<nums.size(); i++) {
            auto it = std::lower_bound(res.begin(), res.end(), nums[i]);
            if(it==res.end()) res.push_back(nums[i]);
            else *it = nums[i];
        }
        return res.size();
    }
};

2. Longest Increasing Subsequence Leetcode Solution Java

public class Solution {
    public int lengthOfLIS(int[] nums) {
        if (nums == null || nums.length == 0) {
            return 0;
        }
        int n = nums.length;
        int[] dp = new int[n];
        Arrays.fill(dp, 1);
        for (int i = 1; i < n; ++i) {
            for (int j = 0; j < i; ++j) {
                if (nums[i] > nums[j]) {
                    dp[i] = Math.max(dp[i], dp[j] + 1);
                }
            }
        }
        int maxLength = Arrays.stream(dp).max().orElse(0);
        return maxLength;
    }
}

3. Longest Increasing Subsequence Solution JavaScript

var lengthOfLIS = function(nums) {
    if (!nums || nums.length === 0) {
        return 0;
    }
    const n = nums.length;
    const dp = new Array(n).fill(1);
    for (let i = 1; i < n; ++i) {
        for (let j = 0; j < i; ++j) {
            if (nums[i] > nums[j]) {
                dp[i] = Math.max(dp[i], dp[j] + 1);
            }
        }
    }
    return Math.max(...dp);
};

4. Longest Increasing Subsequence Solution Python

class Solution(object):
    def lengthOfLIS(self, nums):
        if not nums:
            return 0
        n = len(nums)
        dp = [1] * n
        for i in range(1, n):
            for j in range(i):
                if nums[i] > nums[j]:
                    dp[i] = max(dp[i], dp[j] + 1)
        return max(dp)
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