ในโปรแกรมนี้เราต้อง ใช้การค้นหาแบบไบนารีเพื่อค้นหาการมีอยู่ของลำดับการค้นหาในแผนผังการค้นหาแบบไบนารี ความซับซ้อนของเวลากรณีที่แย่ที่สุดของการค้นหาแบบไบนารีคือ O(n) แต่สำหรับกรณีเฉลี่ย O(log(n))
อัลกอริทึม
Begin Construct binary search tree for the given unsorted data array by inserting data into tree one by one. Take the input of data to be searched in the BST. Now starting from the root node, compare the data with data part of the node. if data < temp->d, move the temp pointer to the left child. if data > temp->d move the temp pointer to the right child. if data = temp->d print the tree depth where it is found and return to main. Else print item not found. End
โค้ดตัวอย่าง
#include<iostream> using namespace std; struct node { int d; node *left; node *right; }; node* CreateNode(int d) { node *newnode = new node; newnode->d = d; newnode->left = NULL; newnode->right = NULL; return newnode; } node* InsertIntoTree(node* root, int d) { node *temp = CreateNode(d); node *t = new node; t = root; if(root == NULL) root = temp; else { while(t != NULL) { if(t->d < d) { if(t->right == NULL) { t->right = temp; break; } t = t->right; } else if(t->d > d) { if(t->left == NULL) { t->left = temp; break; } t = t->left; } } } return root; } void Search(node *root, int d) { int depth = 0; node *temp = new node; temp = root; while(temp != NULL) { depth++; if(temp->d == d) { cout<<"\nitem found at depth: "<<depth; return; } else if(temp->d > d) temp = temp->left; else temp = temp->right; } cout<<"\n item not found"; return; } int main() { char ch; int n, i, a[10] = {93, 53, 45, 2, 7, 67, 32, 26, 71, 76}; node *root = new node; root = NULL; for (i = 0; i < 10; i++) root = InsertIntoTree(root, a[i]); up: cout<<"\nEnter the Element to be searched: "; cin>>n; Search(root, n); cout<<"\n\n\tDo you want to search more...enter choice(y/n)?"; cin>>ch; if(c == 'y' || c == 'Y') goto up; return 0; }
ผลลัพธ์
Enter the Element to be searched: 26 item found at depth: 7 Do you want to search more...enter choice(y/n)? Enter the Element to be searched: 1 item not found Do you want to search more...enter choice(y/n)?