Nice program but too long to get into my head. Looks like you copied this from another site. Write a short program ASAP, else I’m gonna kick your ass.

A few helpful edits:

One of the lines in merge is incorrect- you set temp2’s child final pointer equal to the roots child 0, which is itself. This leads to an infinite loop when trying to print or delete etc.

The corrected version is below:

void btree :: merge ( int k )
{
btnode *temp1, *temp2 ;
temp1 = root -> child[k] ;
temp2 = root -> child[k – 1] ;
temp2 -> count++ ;
temp2 -> value[temp2 -> count] = root -> value[k] ;
temp2 -> child[temp2 -> count] = root -> temp1[0] ; // <– this line is the changed line

Also, I dont understand why your leftshift rightshift and merge all use the root instead of a passed node. Maybe this works, but I found that I had to pass in the node I was currently working on instead of using the root. My full edited rightshift, leftshift, and merge functions are below.

template
void BTree::leftshift( int k, BTreeNode * t){
BTreeNode * temp;
temp = t -> ptr[k-1];
temp->totalKeys++;
temp->keys[temp->totalKeys] = t -> keys[k];
temp->ptr[temp->totalKeys] = t -> ptr[k] -> ptr[0];
temp= t->ptr[k];
t->keys[k] = temp -> keys[1];
temp->ptr[0] = temp-> ptr[1];
temp->totalKeys–;
for (int i=1; i totalKeys; i++){
temp->keys[i] = temp->keys[i+1];
temp->ptr[i] = temp->ptr[i+1];
}
}

template
void BTree::rightshift( int i, BTreeNode * t) {
BTreeNode *temp, *temp2;
temp = t -> ptr[i];
temp2 = t -> ptr[i-1];
for (int j=temp->totalKeys; j >0; j–){
temp->keys[j+1] = temp->keys[j];
temp->ptr[j+1] = temp->ptr[j];
}
temp->ptr[1] = temp-> ptr[0];
temp->totalKeys++;
temp->keys[1] = t->keys[i];
t->keys[i] = temp2 -> keys[temp2->totalKeys];
t->ptr[i]->ptr[0] = temp2 -> ptr[temp2->totalKeys];
temp2->totalKeys–;
}

template
void BTree::merge(int i, BTreeNode * t){
BTreeNode *temp1, *temp2;
temp1 = t -> ptr[i];
temp2 = t ->ptr[i-1];
temp2 -> totalKeys++;
temp2 ->keys[temp2->totalKeys] = t->keys[i];
temp2 ->ptr[temp2->totalKeys] = temp1->ptr[0];
for (int j = 1; j totalKeys; j++ ) {
temp2 -> totalKeys++;
temp2-> keys[temp2->totalKeys] = temp1 -> keys[j];
temp2-> ptr[temp2->totalKeys] = temp1 -> ptr[j];
}
for (int j = i; j totalKeys; j++ ) {
t-> keys[j] = t -> keys[j+1];
t-> ptr[j] = t -> ptr[j+1];
}
t->totalKeys–;
delete temp1;
}