Java | Dynamic Programming
Initialize dp array and ans = 1.
Iterate through nums1 and nums2.
Update dp[i][0] and dp[i][1] based on comparisons with previous elements.
Updating dp[i] (for
Initialize dp array and ans = 1.
Iterate through nums1 and nums2.
Update dp[i][0] and dp[i][1] based on comparisons with previous elements.
- Updating dp[i] (for nums1)
    - Check if the current element in nums1 is greater than or equal to the previous element in nums1:
If nums1[i] >= nums1[i-1], then the non-decreasing subsequence ending at nums1[i-1] can be extended by appending nums1[i]. Update dp[i] = dp[i-1] + 
    - Check if the current element in nums1 is greater than or equal to the previous element in nums2:
If nums1[i] >= nums2[i-1], then the non-decreasing subsequence ending at nums2[i-1] can be extended by appending nums1[i]. Update dp[i] = Math.max(dp[i], dp[i-1][1] + 1).
Update ans with the maximum length found.
Return ans as the maximum length of a non-decreasing subsequence.
- Updating dp[i] (for nums2)
    - Check if the current element in nums2 is greater than or equal to the previous element in nums2:
If nums2[i] >= nums2[i-1], then the non-decreasing subsequence ending at nums2[i-1] can be extended by appending nums2[i]. Update dp[i][1] = dp[i-1][1] + 1.
    - Check if the current element in nums2 is greater than or equal to the previous element in nums1:
If nums2[i] >= nums1[i-1], then the non-decreasing subsequence ending at nums1[i-1] can be extended by appending nums2[i]. Update dp[i][1] = Math.max(dp[i][1], dp[i-1] + 1).

# Code
```java []
class Solution {
    public int maxNonDecreasingLength(int[] nums1, int[] nums2) {
        int[][] dp = new int[nums1.length][2];
        dp[0][0] = 1;
        dp[0][1] = 1;
        int ans = 1;
        for(int i=1;i<nums1.length;i++){
            dp[i][0] = 1;
            dp[i][1] = 1;
            if(nums1[i]>=nums1[i-1]){
                dp[i][0] = dp[i-1][0]+1;
            }
            if(nums1[i]>=nums2[i-1]){
                dp[i][0] = Math.max(dp[i][0],dp[i-1][1]+1);
            }
            if(nums2[i]>=nums2[i-1]){
                dp[i][1] = dp[i-1][1]+1;
            }
            if(nums2[i]>=nums1[i-1]){
                dp[i][1] = Math.max(dp[i][1],dp[i-1][0]+1);
            }
            ans = Math.max(dp[i][0],Math.max(ans,dp[i][1]));
            
        }
        
        
        return ans;
        
    }
}
```
['Array', 'Dynamic Programming', 'Java']