我正在编写代码以创建一个BST，以文本文件中的值填充BST。文本文件包含一个随机的10000个正整数列表，并输出一定的整数。我在打开文件和检索数字时遇到麻烦。
#include<iostream>
#include<fstream>
#include <stdlib.h> //srand, rand
#include <time.h>//clock_t, clock, CLOCKS_PER_SEC
#include<iomanip>
using namespace std;
struct node {
int data;
struct node* left;
struct node* right;
};
struct node* newNode(int data) {
struct node* node = new(struct node); // "new" is like "malloc"
node->data = data;
node->left = NULL;
node->right = NULL;
return(node);
}
struct node* insert(struct node* node, int data) {
// 1. If the tree is empty, return a new, single node
if (node == NULL) {
return(newNode(data));
}
else {
// 2. Otherwise, recur down the tree
if (data <= node->data) node->left = insert(node->left, data);
else node->right = insert(node->right, data);
return(node); // return the (unchanged) node pointer
}
}
/*
Given a binary tree, return true if a node
with the target data is found in the tree. Recurs
down the tree, chooses the left or right
branch by comparing the target to each node.
*/
static int lookup(struct node* node, int target) {
// 1. Base case == empty tree
// in that case, the target is not found so return false
if (node == NULL) {
return(false);
}
else {
// 2. see if found here
if (target == node->data) return(true);
else {
// 3. otherwise recur down the correct subtree
if (target < node->data) return(lookup(node->left, target));
else return(lookup(node->right, target));
}
}
}
void inOrder(struct node *root){
if(root!=NULL){
inOrder(root->left);
cout << root->data<<" ";
inOrder(root->right);
}
}
int main() {
struct node *root= NULL;
char val[10];
ifstream fin; //File reader
clock_t start, end;
fin.open("10000Ints.txt");
if (!fin) {
cerr << "Not able to open 10000Ints.txt file" << endl;
return 1;
}
while(fin >> val){
fin.getline(val, 256, ',');
root = insert(root, atoi(val));
}
cout<<"InOrder Traversal of BST is : "<<endl;
inOrder(root);
cout<<endl;
start = clock();
int find = lookup(root,4);
end = clock();
cout<<fixed<<setprecision(6)<<"Time Taken for Look Up:"<<((end - start))/1000000.0<<endl;
if(!find)
cout<<"\n4 NOT Found";
else
cout<<"4 is Found";
return 0;
}
无法打开文件