718. Maximum Length of Repeated Subarray

718. Maximum Length of Repeated Subarray

标签（空格分隔）： leetcode array medium

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题目

Given two integer arrays ​​A​​​ and ​​B​​, return the maximum length of an subarray that appears in both arrays.

Example 1:

Input: A: [1,2,3,2,1] B: [3,2,1,4,7] Output: 3 Explanation:

Note:

1. 1 <= len(A), len(B) <= 1000
2. 0 <= A[i], B[i] < 100

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思路

本题是个简单的动态规划问题，定义一个数组dp[j]来存储以A[i]为开头的最大子数组长。

代码

//本题是个简单的动态规划问题
class Solution {
public:
    int findLength(vector<int>& A, vector<int>& B) {
        int maxn=0;
        vector<int> dp(B.size()+1);//默认初始化为0
        for(int i=A.size()-1;i>=0;i--)
            for(int j=0;j<B.size();j++)
            {               
                if(A[i]==B[j])
                {
                    dp[j]=1+dp[j+1];
                    maxn = max(maxn,dp[j]);
                }
                else
                   dp[j]=0;
            }
        return maxn;
    }
};