Indexed Sequential Search
In this searching method, first of all, an index file is created, that contains some specific group or division of required record when the index is obtained, then the partial indexing takes less time cause it is located in a specified group.
Note: When the user makes a request for specific records it will find that index group first where that specific record is recorded.
Characteristics of Indexed Sequential Search:
- In Indexed Sequential Search a sorted index is set aside in addition to the array.
- Each element in the index points to a block of elements in the array or another expanded index.
- The index is searched 1st then the array and guides the search in the array.
Note: Indexed Sequential Search actually does the indexing multiple time, like creating the index of an index.
Explanation by diagram “Indexed Sequential Search”:
Code:
C
// C program for Indexed Sequential Search#include <stdio.h>#include <stdlib.h>void indexedSequentialSearch(int arr[], int n, int k){ int elements[20], indices[20], temp, i, set = 0; int j = 0, ind = 0, start, end; for (i = 0; i < n; i += 3) { // Storing element elements[ind] = arr[i]; // Storing the index indices[ind] = i; ind++; } if (k < elements[0]) { printf("Not found"); exit(0); } else { for (i = 1; i <= ind; i++) if (k <= elements[i]) { start = indices[i - 1]; end = indices[i]; set = 1; break; } } if (set == 0) { start = indices[i - 1]; end = n; } for (i = start; i <= end; i++) { if (k == arr[i]) { j = 1; break; } } if (j == 1) printf("Found at index %d", i); else printf("Not found");}// Driver codevoid main(){ int arr[] = { 6, 7, 8, 9, 10 }; int n = sizeof(arr) / sizeof(arr[0]); // Element to search int k = 8; indexedSequentialSearch(arr, n, k);} |
Java
// Java program for Indexed Sequential Searchimport java.io.*;class GFG { static void indexedSequentialSearch(int arr[], int n, int k) { int elements[] = new int[20]; int indices[] = new int[20]; int temp, i; int j = 0, ind = 0, start = 0, end = 0, set = 0; for (i = 0; i < n; i += 3) { // Storing element elements[ind] = arr[i]; // Storing the index indices[ind] = i; ind++; } if (k < elements[0]) { System.out.println("Not found"); return; } else { for (i = 1; i <= ind; i++) if (k <= elements[i]) { start = indices[i - 1]; set = 1; end = indices[i]; break; } } if (set == 0) { start = indices[i - 1]; end = n; } for (i = start; i <= end; i++) { if (k == arr[i]) { j = 1; break; } } if (j == 1) System.out.println("Found at index " + i); else System.out.println("Not found"); } // Driver code public static void main(String[] args) { int arr[] = { 6, 7, 8, 9, 10 }; int n = arr.length; // Element to search int k = 8; indexedSequentialSearch(arr, n, k); }}// This code is contributed by shs.. |
Python3
# Python program for Indexed# Sequential Searchdef indexedSequentialSearch(arr, n, k): elements = [0] * 20 indices = [0] * 20 j, ind, start, end = 0, 0, 0, 0 set_flag = 0 for i in range(0, n, 3): # Storing element elements[ind] = arr[i] # Storing the index indices[ind] = i ind += 1 if k < elements[0]: print("Not found") exit(0) else: for i in range(1, ind + 1): if k <= elements[i]: start = indices[i - 1] end = indices[i] set_flag = 1 break if set_flag == 0: start = indices[i-1] end = n for i in range(start, end + 1): if k == arr[i]: j = 1 break if j == 1: print("Found at index", i) else: print("Not found")# Driver codeif __name__ == "__main__": arr = [6, 7, 8, 9, 10] n = len(arr) # Element to search k = 8 # Function call indexedSequentialSearch(arr, n, k)# This code is contributed by Ryuga |
C#
// C# program for Indexed Sequential Searchusing System;class GFG { static void indexedSequentialSearch(int []arr, int n, int k){ int []elements = new int[20]; int []indices = new int[20]; int i; int j = 0, ind = 0, start=0, end=0, set = 0; for (i = 0; i < n; i += 3) { // Storing element elements[ind] = arr[i]; // Storing the index indices[ind] = i; ind++; } if (k < elements[0]) { Console.Write("Not found"); return; } else { for (i = 1; i <= ind; i++) if (k <= elements[i]) { start = indices[i - 1]; set = 1; end = indices[i]; break; } } if(set == 0) { start = indices[i-1]; end = n-1; } for (i = start; i <= end; i++) { if (k == arr[i]) { j = 1; break; } } if (j == 1) Console.WriteLine("Found at index "+ i); else Console.WriteLine("Not found");}// Driver code public static void Main () { int []arr = { 6, 7, 8, 9, 10 }; int n = arr.Length; // Element to search int k = 10; indexedSequentialSearch(arr, n, k); }}// This code is contributed by shs.. |
PHP
<?php// PHP program for Indexed Sequential Searchfunction indexedSequentialSearch($arr, $n, $k){ $elements = array(); $indices = array(); $temp = array(); $j = 0; $ind = 0; $start=0; $end=0; $set = 0; for ($i = 0; $i < $n; $i += 3) { // Storing element $elements[$ind] = $arr[$i]; // Storing the index $indices[$ind] = $i; $ind++; } if ($k < $elements[0]) { echo "Not found"; } else { for ($i = 1; $i <=$ind; $i++) if ($k < $elements[$i]) { $start = $indices[$i - 1]; $set = 1; $end = $indices[$i]; break; } } if($set == 1) { $start = $indices[$i-1]; $end = $n; } for ($i = $start; $i <=$end; $i++) { if ($k == $arr[$i]) { $j = 1; break; } } if ($j == 1) echo "Found at index ", $i; else echo "Not found";}// Driver code$arr = array( 6, 7, 8, 9, 10 );$n = count($arr);// Element to search$k = 10;indexedSequentialSearch($arr, $n, $k);// This code is contributed by shs..?> |
Output:
Found at index 2
Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.
