Common Subsequence Time Limit: 1000MS Memory Limit: 10000KTotal Submissions: 54754 Accepted: 22811
Description
A subsequence of a given sequence is the given sequence with some elements (possible none) left out. Given a sequence X = < x1, x2, ..., xm > another sequence Z = < z1, z2, ..., zk > is a subsequence of X if there exists a strictly increasing sequence < i1, i2, ..., ik > of indices of X such that for all j = 1,2,...,k, x ij = zj. For example, Z = < a, b, f, c > is a subsequence of X = < a, b, c, f, b, c > with index sequence < 1, 2, 4, 6 >. Given two sequences X and Y the problem is to find the length of the maximum-length common subsequence of X and Y.Input
The program input is from the std input. Each data set in the input contains two strings representing the given sequences. The sequences are separated by any number of white spaces. The input data are correct.Output
For each set of data the program prints on the standard output the length of the maximum-length common subsequence from the beginning of a separate line.Sample Input
abcfbc abfcab programming contest abcd mnpSample Output
4 2 0
import java.util.Scanner; /** * 类说明 * * <pre> * Modify Information: * Author Date Description * ============ =========== ============================ * DELL 2017年8月2日 Create this file * </pre> * */ public class Main { /** * 最长公共子序列问题， 给定 两个字符串 求 这两个字符串的公共子序列 * 确认这个公式很重要. * * 动态规划问题： * dp[i+1][j+1] = { * dp[i][j] +1, dp[i][j+1], dp[j+1][i] // * dp[i+1][j] ,dp[i][j+1] * } */ public int getLongestCommonString(String str1, String str2){ int[][] dp = new int[str1.length()+1][str2.length()+1]; char[] strChar1 = str1.toCharArray(); char[] strChar2 = str2.toCharArray(); for(int i = 0; i < strChar1.length; i++){ for(int j = 0; j < strChar2.length; j++){ if(strChar1[i] == strChar2[j]){ dp[i+1][j+1] = dp[i][j] +1; }else{ dp[i+1][j+1] = Math.max(dp[i+1][j], dp[i][j+1]); } } } return dp[str1.length()][str2.length()]; } /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub String str1 = "addadbs"; String str2 ="hdgsfvab"; String str3 = "abcfbc"; String str4 ="abfcab"; Scanner cin = new Scanner(System.in); String str5 = ""; String str6 = ""; while(cin.hasNext()){ str5 = cin.next(); str6 = cin.next(); int ans = new Main().getLongestCommonString(str5, str6); System.out.println(ans); } } } wangxiaoming 认证博客专家 架构 Spring Boot Redis 博客是很好的总结和记录工具，如果有问题，来不及回复，关注微信公众号：程序员开发者社区，获取我的联系方式，向我提问，也可以给我发送邮件,联系 1275801617@qq.com
