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所以我写了这段代码来添加元素到二叉树。如下图所示。BST不添加元素
typedef struct node{
int key;
node *right;
node *left;
}*nodePtr;
nodePtr root = NULL // As global variable.
void addElement(int key, nodePtr tempRoot){
if(tempRoot!=NULL){
if(tempRoot->key > key){
if(tempRoot->left!=NULL)
addElement(key, tempRoot->left);
else
tempRoot->left = createLeaf(key);
}
else if(tempRoot->key < key){
if(tempRoot->right!=NULL)
addElement(key, tempRoot->right);
else
tempRoot->right = createLeaf(key);
}
}else if(tempRoot==NULL)
tempRoot = createLeaf(key);
}
int main(){
int arr[] = {50,45,23,10,8,1,2,54,6,7,76,78,90,100,52,87,67,69,80,90};
for(int i=0; i<20; i++){
addElement(arr[i], root);
}
return 0;
}
问题是这个代码在我尝试打印树时没有向树添加任何东西。但是,如果我用这段代码替换代码的最后部分,
else if(root==NULL)
root = createLeaf(key);
为什么会发生这种情况?