最长公共子序列

//最长公共子序列//最长公共子序列地归解法package wkx;import java.io.IOException;public class Test { private static int LCSLength(char[] A, char[] B, int[][] m, int[][] s,int i, int j) {if (i < 0 || j < 0)return 0;if (m[i][j] != 0)return m[i][j];if (A[i] == B[j]) {s[i][j] = 1;m[i][j] = LCSLength(A, B, m, s, i - 1, j - 1) + 1;} else {int a = LCSLength(A, B, m, s, i - 1, j);int b = LCSLength(A, B, m, s, i, j - 1);if (a > b) {s[i][j] = 2;m[i][j] = a;} else {s[i][j] = 3;m[i][j] = b;}}return m[i][j];}private static void LCS(char[] A, int[][] s, int i, int j,StringBuffer str) {if (i < 0 || j < 0)return;if (s[i][j] == 1) {str.append(A[i]);LCS(A, s, i - 1, j - 1,str);} else if (s[i][j] == 2) {LCS(A, s, i - 1, j,str);} else {LCS(A, s, i, j - 1,str);}}public static void main(String[] args) throws IOException {String A = "ASSBDGCGDHDERDFGG";String B = "ASBSSCDEF";if (A.length() < B.length()) {String t = A;A = B;B = t;}int[][] m = new int[100][100];int[][] s = new int[100][100];System.out.println("Total : "+ LCSLength(A.toCharArray(), B.toCharArray(), m, s,A.length() - 1, B.length() - 1));StringBuffer str=new StringBuffer();LCS(A.toCharArray(), s, A.length() - 1, B.length() - 1,str);System.out.println(str.reverse());}}