74 lines
2.4 KiB
Java
74 lines
2.4 KiB
Java
import java.util.Scanner;
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public class TernarySearch{
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/**
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* @param arr The **Sorted** array in which we will search the element.
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* @param value The value that we want to search for.
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* @return The index of the element if found.
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* Else returns -1.
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*/
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public static int ternarySearch(int[] arr, int value){
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return ternarySearch(arr, value, 0, arr.length - 1);
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}
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/**
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* @param arr The **Sorted** array in which we will search the element.
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* @param key The value that we want to search for.
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* @param start The starting index from which we will start Searching.
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* @param end The ending index till which we will Search.
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* @return Returns the index of the Element if found.
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* Else returns -1.
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*/
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public static int ternarySearch(int[] arr, int key, int start, int end) {
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if (start > end){
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return -1;
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}
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/* First boundary: add 1/3 of length to start */
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int mid1 = start + (end - start) / 3;
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/* Second boundary: add 2/3 of length to start */
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int mid2 = start + 2 * (end - start) / 3;
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if (arr[mid1] == key) {
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return mid1;
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}
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else if (arr[mid2] == key) {
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return mid2;
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}
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/* Search the first (1/3) rd part of the array.*/
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else if (key < arr[mid1]) {
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return ternarySearch(arr, key, start, mid1 - 1);
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}
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/* Search 3rd (1/3)rd part of the array */
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else if (key > arr[mid2]) {
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return ternarySearch(arr, key, mid2 + 1, end);
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}
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/* Search middle (1/3)rd part of the array */
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else {
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return ternarySearch(arr, key, mid1, mid2);
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}
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}
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public static void main(String[] args) {
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Scanner s = new Scanner(System.in);
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System.out.println("Enter number of elements in the array");
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int n = s.nextInt();
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int arr[] = new int[n];
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System.out.println("Enter the elements of the Sorted array");
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for (int i= 0; i < n; i++){
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arr[i] = s.nextInt();
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}
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System.out.println("Enter element to search for : ");
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int k = s.nextInt();
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int ans = ternarySearch(arr, k);
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if (ans == -1) {
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System.out.println(" The element is not present in the array.");
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}
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else {
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System.out.println("The element is present at the position " + (ans+1));
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}
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}
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} |