動態規劃之最長公共子序列---java實現

 

 

public class LCSProblem { public static void main(String[] args) { String[] x = {"", "A", "B", "C", "B", "D", "A", "B"}; String[] y = {"", "B", "D", "C", "A", "B", "A"}; int[][] b = getLength(x, y); Display(b, x, x.length-1, y.length-1); } public static int[][] getLength(String[] x, String[] y) { int[][] b = new int[x.length][y.length]; int[][] c = new int[x.length][y.length]; for(int i=1; i<x.length; i++) { for(int j=1; j<y.length; 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] = 0; } else { c[i][j] = c[i][j-1]; b[i][j] = -1; } } } return b; } public static void Display(int[][] b, String[] x, int i, int j) { if(i == 0 || j == 0) return; if(b[i][j] == 1) { Display(b, x, i-1, j-1); System.out.print(x[i] + " "); } else if(b[i][j] == 0) { Display(b, x, i-1, j); } else if(b[i][j] == -1) { Display(b, x, i, j-1); } } }

 

 

 

尊重原創http://yoyo08.javaeye.com/blog/419447