二叉树三种遍历方式代码实现

void first_visit(node *current)//前序遍历

{

    printf("%d ",current->entry);

    if (current->left != NULL) first_visit(current->left);

    if (current->right != NULL) first_visit(current->right);

}

void last_visit(node *current)//后序遍历

{

    if (current->left != NULL) first_visit(current->left);

    if (current->right != NULL) first_visit(current->right);

    printf("%d ",current->entry);

}

void middle_visit(node *current)//中序遍历

{

    if (current->left != NULL) first_visit(current->left);

    printf("%d ",current->entry);

    if (current->right != NULL) first_visit(current->right);

}

/*

从代码来看，很好的对应了每种遍历方式的名称，前序遍历是先输出当前结点，再尝试访问左结点和右结点，就是输出语句的位置在之前，中间和之后

*/