红黑树的旋转（C语言）

 1 //左旋
 2 static void rbTreeLeftRotate(RBTree *rbTree, RBTreeNode *x)
 3 {
 4     RBTreeNode *y;
 5 
 6     y = x->right;        //设置一个指针型变量来存放x右孩子的地址，
 7     x->right = y->left;    //此处将x的右孩子替换成y的左孩子
 8 
 9     if (y->left !=NULL)
10         y->left->parent = x;
11     
12     y->parent = x->parent;
13 
14     if (x->parent == NULL)
15         *rbTree = y;
16     else 
17     {
18     if (x->parent->left == x)
19         x->parent->left = y;
20     else
21         x->parent->right = y;    
22     }
23     y->left = x;
24     x->parent  = y;
25 }

 1 //右旋
 2 static void rbTreeRightRotate(RBTree *rbTree, RBTreeNode *x)
 3 {
 4     RBTreeNode *y;
 5 
 6     y = x->left;
 7     x->left = y->right;
 8 
 9     if (y->right !=NULL)
10         y->right->parent  = x;    //link  y->right to x->left
11 
12     y->parent = x->parent ;        
13     if (x->parent == NULL)        //link  x->parent to y
14         *rbTree = y;
15     else
16         {
17         if (x->parent->left = x)
18             x->parent->left = y;
19         else20           x->parent->right = y;
21         }
22     y->right = x;
23     x->parent = y;
24 
25 }