LcsLength.rar_最长 公共子序列 算法_最长公共子序列

public class LcsLength { public static int lcsLength(char []x,char []y,int [][]b) { int m=x.length-1; int n=y.length-1; int[][] c=new int[m+1][n+1]; for(int i=1;i<=m;i++) c[i][0]=0; for(int i=1;i<=n;i++) c[0][i]=0; for(int i=1;i<=m;i++) for(int j=1;j<=n;j++) { if(x[i]==y[j]) { c[i][j]=c[i-1][j-1]+1; b[i][j]=1; } else if(c[i-1][j]>=c[i][j-1]) { c[i][j]=c[i-1][j]; b[i][j]=2; } else { c[i][j]=c[i][j-1]; b[i][j]=3; } } int i=m;int j=n; lcs(i,j,x,b); return c[m][n]; } public static void lcs(int i,int j,char []x,int [][]b) { if(i==0||j==0) return; if(b[i][j]==1) { lcs(i-1,j-1,x,b); System.out.print(x[i]+","); } else if(b[i][j]==2)lcs(i-1,j,x,b); else lcs(i,j-1,x,b); } public static void main(String args[]) { char[] x={'a','b','c','b','d','b'}; char[] y={'a','c','b','b','a','b','d','b','b'}; int[][] b=new int[x.length][y.length]; System.out.print("最长公共子序列："); int n=lcsLength(x,y,b); System.out.println(); System.out.println("其长度为："+n); } }