delete tree.txt

来自「It is an ebook about trees」· 文本 代码 · 共 64 行

Write a C program to delete a tree (i.e, free up its nodes) 

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struct Bintree{
    int element;
    struct Bintree *left;
    struct Bintree *right;
};

typedef struct Bintree* Tree;

Tree findMin( Tree T) // Recursively finding min element
{
    if( !T )
        return NULL;
    else if( !T->left )
        return T;
    else 
        return findMin( T->left );
}


Tree DeleteTree( int x, Tree T) // To Delete whole tree recursively
{
    if(!T)
    {
        DeleteTree(T->left);
        DeleteTree(T->right);
        free(T);
    }
    return NULL;
}

Tree DeleteNode( int x, Tree T ) // To Delete a Node with element x
{
    Tree tmp;
    if(!T)
        return NULL;
    else if( x < T->element )
        T->left = DeleteNode( x, T->left );
    else if( x > T->element )
        T->right = DeleteNode( x, T->right );
    else if( T->left && T->right )
    {
        tmp = findMin( T-> right );
        T->element = tmp->element;
        T->right = DeleteNode( T->element, T->right );
    }
    else
    {
        tmp = T;
        if( T->left )
            T = T->left;
        else if( T->right )
            T = T->right;
        free(tmp);
    }
}