b树的实现

花了蛮长时间实现的b树插入操作。有时间再实现其他操作。

#include <stdio.h>
#include <stdlib.h>
#define M 5

enum KeyStatus { Duplicate,SearchFailure,Success,InsertIt,LessKeys };
struct node {
        int n; /* n < M No. of keys in node will always less than order of B tree */
        int keys[M-]; /*array of keys*/
        struct node *p[M]; /* (n+1 pointers will be in use) */
}*root=NULL;

int pushIn(struct node* currentNode, int key , struct node* toInsertNode){
    int i=;

    for(i=currentNode->n -;i>=-;i--){
        if(key < currentNode->keys[i]){
            currentNode->keys[i+]=currentNode->keys[i];
      currentNode->p[i+]=currentNode->p[i+];
        }
        else{
            currentNode->keys[i+]=key;
      currentNode->p[i+]= toInsertNode;
            break;
        }

    }
  currentNode->n++;
    return ;
}

int searchNode(struct node* currentNode, int key, int *downNodeIndex){
    int i=;
  for(i=currentNode->n -;i>=;i--){
    if(key== currentNode->keys[i]){
      return Success;
    }else if (key < currentNode->keys[i]){
      if( i> ){
        continue;
      }else {
        *downNodeIndex=;
      }
    }else{
      *downNodeIndex=i+;
      break;
    }
  }
  return SearchFailure;
}

int splitNode(struct node* currentNode, int toInsertkey, struct node* toInsertNode, int *toLiftKey, struct node** toLiftNode ){
  struct node* rightSplittedNode = calloc(sizeof(struct node),);
  int i=;
  int leftMedian=((M-)/ - );
  int rightMedian=(M-)/;
  if(toInsertkey > currentNode->keys[rightMedian]){
    for(i=M-;i>=rightMedian+;i--){
      pushIn(rightSplittedNode,currentNode->keys[i-],currentNode->p[i]);
      currentNode->n--;
    }
    pushIn(rightSplittedNode,toInsertkey, toInsertNode);
    *toLiftKey=currentNode->keys[currentNode->n-];
    rightSplittedNode->p[]=currentNode->p[currentNode->n];
    *toLiftNode=rightSplittedNode;
    currentNode->n--;
  }
  else {
    for(i=M-;i>=rightMedian+;i--){
      pushIn(rightSplittedNode,currentNode->keys[i-],currentNode->p[i]);
      currentNode->n--;
    }
    pushIn(currentNode,toInsertkey, toInsertNode);
    *toLiftKey=currentNode->keys[currentNode->n-];
    rightSplittedNode->p[]=currentNode->p[currentNode->n];
    *toLiftNode=rightSplittedNode;
    currentNode->n--;
  }

  return ;

}

int pushDown(struct node* currentNode, int toInsertKey, int* toLiftKey, struct node** toLiftNode){

  int downNodeIndex;
  struct  node* toInsertNode;
  int rc;

  if( NULL == currentNode){
    *toLiftNode=NULL;
    (*toLiftKey)=toInsertKey;
    return InsertIt;
  }

  if( Success == searchNode(currentNode,toInsertKey, &downNodeIndex) ){
    return Duplicate;
  }

  rc=pushDown(currentNode->p[downNodeIndex], toInsertKey, toLiftKey, toLiftNode);

  if(InsertIt !=rc){
    return rc;
  }

  if( currentNode->n < M- ){
    pushIn(currentNode,*toLiftKey,*toLiftNode);
    return Success;
  }else {
    toInsertKey=(*toLiftKey);
    toInsertNode=*toLiftNode;
    splitNode(currentNode,toInsertKey,toInsertNode,toLiftKey,toLiftNode);
    printf("toLiftNode %d\n", toLiftNode);
  }

  return rc;

}

int insert(struct node * currentNode, int key){
  struct node* toLiftNode;
  struct node* newRoot;
  int toLiftKey;
  int rc;
  toLiftNode=NULL;
  rc=pushDown(currentNode,key, &toLiftKey,&toLiftNode);

  if(InsertIt == rc ){
    newRoot =  calloc( sizeof(struct node),);
    newRoot->n=;
    newRoot->keys[]=toLiftKey;
    newRoot->p[]=root;
    newRoot->p[]=toLiftNode;
    root=newRoot;
    rc=Success;
  }
  return rc;
}

void display(struct node *ptr, int blanks , int level)
{
    if (ptr)
    {
        int i;
          printf("level:%d nodeAddr:%ld   ",level, ptr);
        for(i=; i<=blanks; i++)
            printf(" ");
        for (i=; i < ptr->n; i++)
            printf("%d ",ptr->keys[i]);
        printf("\n");
        for (i=; i <= ptr->n; i++)
            display(ptr->p[i], blanks+,level+);
    }/*End of if*/
}/*End of display()*/

int main(int argc, char const *argv[]) {
  insert(root,*);
  insert(root,*);
  insert(root,*);
  insert(root,*);
  display(root,,);
  insert(root,);
  insert(root,*);
  insert(root,*);
  insert(root,*);
  display(root,,);
  insert(root,*);
  insert(root,);
  insert(root,);
  insert(root,);
  insert(root,);
  insert(root,);
  insert(root,);
  insert(root,);
  insert(root,);
  insert(root,);
  insert(root,);
  insert(root,);

  display(root,,);
  return ;
}