6-20 No Less Than X in BST（20 分）

You are supposed to output, in decreasing order, all the elements no less than X in a binary search tree T.

Format of function:

void Print_NLT( Tree T,  int X );

where Tree is defined as the following:

typedef struct TreeNode *Tree;
struct TreeNode {
    int Element;
    Tree  Left;
    Tree  Right;
};

The function is supposed to use Output(X) to print X.

Sample program of judge:

#include <stdio.h>
#include <stdlib.h>

typedef struct TreeNode *Tree;
struct TreeNode {
    int Element;
    Tree  Left;
    Tree  Right;
};

Tree BuildTree(); /* details omitted */
void Output( int X ); /* details omitted */

void Print_NLT( Tree T,  int X );

int main()
{
    Tree T;
    int X;

    T = BuildTree();
    scanf("%d", &X);
    Print_NLT( T, X );
    printf("End
");

    return 0;
}

/* Your function will be put here */

Sample Output 1 (for the tree shown in Figure 1):

92 91 90 85 81 80 End

Figure 1

Sample Output 2 (for the tree shown in Figure 2):

End

Figure 2

 

哈哈 好巧妙，树的遍历就是好用

 

代码：

void Print_NLT( Tree T,  int X )
{
    if(T == NULL)return;
    Print_NLT(T -> Right,X);
    if(T -> Element >= X)printf("%d ",T -> Element);
    Print_NLT(T -> Left,X);
}