最优二叉搜索树问题

java实现：

public class 最优二叉搜索树问题 {public static void main(String[] args) {// TODO Auto-generated method stubdouble p[] = {0,0.15,0.10,0.05,0.10,0.20};double q[] = {0.05,0.10,0.05,0.05,0.05,0.10};double p1[] = {0,0.04,0.06,0.08,0.02,0.10,0.12,0.14};double q1[] = {0.06,0.06,0.06,0.06,0.05,0.05,0.05,0.05};Optimal_BST(p, q, p.length-1);System.out.println();Optimal_BST(p1, q1, p1.length-1);}public static void Optimal_BST(double p[], double q[],int n) {double e[][] = new double[n+2][n+1];double w[][] = new double[n+2][n+1];int root[][] = new int[n+1][n+1];for(int i = 1; i<= n+1; i++) {e[i][i-1] = q[i-1];w[i][i-1] = q[i-1];}for(int l = 1; l <= n; l++) {for(int i = 1; i<= n-l+1; i++) {int j = i+l-1;e[i][j] = 1e9;w[i][j] = w[i][j-1] + p[j] + q[j];for(int r = i; r<=j; r++) {double t = e[i][r-1] + e[r+1][j] + w[i][j];if(t < e[i][j]) {e[i][j] = t;root[i][j] = r;}}}}System.out.println(e[1][n]);construct_optimal_BST(root, 1, n);}//打印树根public static void construct_optimal_BST(int root[][], int i, int j) {if(i>j || root[i][j] == 0) {return ;}else {int r = root[i][j];System.out.print(r+" ");construct_optimal_BST(root, i, r-1);construct_optimal_BST(root, r+1, j);}}}