lintcode77最长公共子序列（动态规划medium）

public class Solution {    /**     * @param A, B: Two strings.     * @return: The length of longest common subsequence of A and B.     */    public int longestCommonSubsequence(String A, String B) {        int m=A.length();        int n=B.length();        if(m==0||n==0){            return 0;        }        int [][]arr=new int[m+2][n+2];         for(int i=1;i<=m;i++){            for(int j=1;j<=n;j++){                if(A.charAt(i-1) == B.charAt(j-1)){                    arr[i][j]=arr[i-1][j-1]+1;                }else{                    arr[i][j]=Math.max(arr[i-1][j],arr[i][j-1]);                }            }        }        return arr[m][n];    }}细节处理： if(A.charAt(i-1) == B.charAt(j-1)){                    arr[i][j]=arr[i-1][j-1]+1;                }else{                    arr[i][j]=Math.max(arr[i-1][j],arr[i][j-1]);                }