718. Maximum Length of Repeated Subarray

Given two integer arrays nums1 and nums2, return the maximum length of a subarray that appears in both arrays.

Example 1:

Input: nums1 = [1,2,3,2,1], nums2 = [3,2,1,4,7]
Output: 3
Explanation: The repeated subarray with maximum length is [3,2,1].

Example 2:

Input: nums1 = [0,0,0,0,0], nums2 = [0,0,0,0,0]
Output: 5

Constraints:

• 1 <= nums1.length, nums2.length <= 1000
• 0 <= nums1[i], nums2[i] <= 100

class Solution {
    public int findLength(int[] nums1, int[] nums2) {
        int n1 = nums1.length, n2 = nums2.length;
        int[][] dp = new int[n1 + 1][n2 + 1];
        int res = 0;
        for(int i = 0; i <= n1; i++) {
            for(int j = 0; j <= n2; j++) {
                if(i == 0 || j == 0) {
                    dp[i][j] = 0;
                    continue;
                }
                if(nums1[i - 1] == nums2[j - 1]) {
                    dp[i][j] = 1 + dp[i - 1][j - 1];
                    res = Math.max(dp[i][j], res);
                }
            }
        }
        return res;
    }
}

典中典dp用处之一---匹配