連結：https://www.nowcoder.com/questionTerminal/02e7cc263f8a49e8b1e1dc9c116f7602
來源：牛客網

public int findLongest(String A, int n, String B, int m) {
        char[] arrA=A.toCharArray();
        char[] arrB=B.toCharArray();
        int[][] dp=new int[n][m];
        int max=0;
        for(int i=0;i<n;i++){
            if(arrA[i]==arrB[0])
                dp[i][0]=1;
        }
        for(int j=1;j<m;j++){
            if(arrB[j]==arrA[0])
                dp[0][j]=1;
        }
        for(int i=1;i<n;i++){
            for(int j=1;j<m;j++){
                if(arrA[i]==arrB[j])
                    max=Math.max(dp[i][j]=dp[i-1][j-1]+1, max);
            }
        }
        return max;
    }