Everytime I use this my avlRotate function, it drops some elements from the tree. z is the node in which imbalance was detected, y is its subtree node having the greater height, x is the newly inserted node. This function is called immediately after a single insertion.
#define RESTRUCTURE a->left = t0; a->right = t1; c->left = t2; c->right = t3; b->left = a; b->right = c;
avlTree avlRotate(avlTree z,avlTree y,avlTree x)
{
avlTree a,b,c;
avlTree t0,t1,t2,t3;
if(y==z->left && x==y->left) //single rotation
{
a=x;b=y;c=z;
t0=a->left;
t1=a->right;
t2=b->right;
t3=c->right;
RESTRUCTURE
c->height[0] = y->height[1];
}
else if(y==z->right && x==y->right) //single rotation
{
a=z;b=y;c=x;
t0=a->left;
t1=b->left;
t2=c->left;
t3=c->right;
RESTRUCTURE
a->height[1] = y->height[0];
}
else if(y==z->right && x==y->left) //double rotation
{
a=z;b=x;c=y;
t0=a->left;
t1=b->left;
t2=b->right;
t3=c->right;
RESTRUCTURE
a->height[1] = x->height[0];
c->height[0] = x->height[1];
}
else if(y==z->left && x==y->right) //double rotation
{
a=y;b=x;c=z;
t0=a->left;
t1=b->left;
t2=b->right;
t3=c->right;
RESTRUCTURE
a->height[1] = x->height[0];
c->height[0] = x->height[1];
}
printf("\nRem parts:\n");
printf("{%d %d} {%d %d} {%d %d}\n",a->part->range[0],a->part->range[1],b->part->range[0],b->part->range[1],c->part->range[0],c->part->range[1]);
printf("\n\n");
b->height[0] = ( (a->height[0] > a->height[1]) ? (a->height[0])+1 : (a->height[1])+1 );
b->height[1] = ( (c->height[0] > c->height[1]) ? (c->height[0])+1 : (c->height[1])+1 );
a->balFactor = a->height[0] - a->height[1];
b->balFactor = b->height[0] - b->height[1];
c->balFactor = c->height[0] - c->height[1];
return(b);
}
The function is called with:
if(a->balFactor > 1 || a->balFactor < -1)
{
printf("imbalance fside=%d pside=%d\n",*finalSide,*prevSide);
if(*finalSide == 0)
{yLike = a->left;}
else
{yLike = a->right;}
if(*prevSide == 0)
{xLike = yLike->left;}
else
{xLike = yLike->right;}
printf("passing to rotate %u %u %u\n",a,yLike,xLike);
printf("{%d %d} {%d %d} {%d %d}\n",a->part->range[0],a->part->range[1],yLike->part->range[0],yLike->part->range[1],xLike->part->range[0],xLike->part->range[1]);
a = avlRotate(a,yLike,xLike);
avlInOrderTraversal(a,0);
printf("{%d %d} {%d %d} {%d %d}\n",a->left->part->range[0],a->left->part->range[1],a->part->range[0],a->part->range[1],a->right->part->range[0],a->right->part->range[1]);
}
in the insert function.
Output:
a->height[0]=1 a->height[1]=0
BALANCE FACTOR = 1
16 to 18
51 to 53
a->height[0]=0 a->height[1]=1
BALANCE FACTOR = -1
a->height[0]=2 a->height[1]=0
BALANCE FACTOR = 2
imbalance fside=0 pside=1
passing to rotate 147992552 147992584 147992616
{51 53} {16 18} {41 41}
Rem parts:
{16 18} {41 41} {51 53}
51 to 53
a->height[0]=0 a->height[1]=1
BALANCE FACTOR = -1
51 to 53
60 to 61
a->height[0]=1 a->height[1]=1
BALANCE FACTOR = 0
4 to 6
51 to 53
60 to 61
Is something obviously incorrect with this function?
Note: Each node stores a range, for eg. 3 to 5.