300. Longest Increasing Subsequence
Given an integer array nums, return the length of the longest strictly increasing subsequence.
A subsequence is a sequence that can be derived from an array by deleting some or no elements without changing the order of the remaining elements. For example, [3,6,2,7] is a subsequence of the array [0,3,1,6,2,2,7].
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
Constraints:
- 1 <= nums.length <= 2500
- -104 <= nums[i] <= 104
class Solution {
public int lengthOfLIS(int[] nums) {
int maxLen = 1;
int[] dp = new int[nums.length];
for(int i=0;i<nums.length;i++){
dp[i] = 1;
for(int j=0;j<i;j++){
// It means next number contributes to increasing sequence.
if(nums[j]<nums[i]){
dp[i] = Math.max(dp[i], dp[j]+1);
}
}
maxLen = Math.max(maxLen,dp[i]);
}
return maxLen;
}
}