|
| 1 | +--- |
| 2 | +id: Fractal-Search-Algorithm |
| 3 | +title: Fractal Search Algorithm |
| 4 | +sidebar_label: Fractal Search Algorithm |
| 5 | +tags: |
| 6 | + - Advanced |
| 7 | + - Search Algorithms |
| 8 | + - Fractals |
| 9 | + - CPP |
| 10 | + - Python |
| 11 | + - Java |
| 12 | + - JavaScript |
| 13 | + - DSA |
| 14 | +description: "This is a detailed explanation and implementation of the Fractal Search Algorithm." |
| 15 | + |
| 16 | +--- |
| 17 | + |
| 18 | +## What is the Fractal Search Algorithm? |
| 19 | + |
| 20 | +The Fractal Search Algorithm (FSA) is an advanced search algorithm inspired by the fractal nature of various processes and patterns in nature. It leverages the self-similarity and recursive properties of fractals to efficiently search through complex spaces. |
| 21 | + |
| 22 | +## Algorithm for Fractal Search |
| 23 | + |
| 24 | +1. **Initialization**: Define the search space and initialize the fractal pattern. |
| 25 | +2. **Recursive Division**: Recursively divide the search space into smaller subspaces following the fractal pattern. |
| 26 | +3. **Search Subspaces**: Evaluate the subspaces to find the target element. |
| 27 | +4. **Merge Results**: Combine the results from the subspaces to determine the final position of the target element. |
| 28 | + |
| 29 | +## How does Fractal Search work? |
| 30 | + |
| 31 | +- FSA divides the search space into self-similar subspaces recursively. |
| 32 | +- It searches each subspace individually, combining results to identify the target element. |
| 33 | +- This approach reduces the search space significantly, improving efficiency. |
| 34 | + |
| 35 | + |
| 36 | +## Problem Description |
| 37 | + |
| 38 | +Given a complex search space, implement the Fractal Search Algorithm to find the target element. If the element is not present, the algorithm should indicate that as well. |
| 39 | + |
| 40 | +## Examples |
| 41 | + |
| 42 | +**Example 1:** |
| 43 | +Input: |
| 44 | +search_space = [1, 3, 5, 7, 9] |
| 45 | +target = 5 |
| 46 | +Output: 2 |
| 47 | + |
| 48 | +**Example 2:** |
| 49 | +Input: |
| 50 | +search_space = [2, 4, 6, 8, 10] |
| 51 | +target = 7 |
| 52 | +Output: -1 |
| 53 | + |
| 54 | +## Your Task |
| 55 | + |
| 56 | +Complete the function `fractal_search()` which takes a list `search_space` and an integer `target` as input parameters and returns the index of the target element. If the element is not present, return -1. |
| 57 | + |
| 58 | +Expected Time Complexity: $O(\log n)$ |
| 59 | +Expected Auxiliary Space: $O(n)$ |
| 60 | + |
| 61 | +## Constraints |
| 62 | + |
| 63 | +- $1 <= n <= 10^6$ |
| 64 | +- $1 <= search_space[i] <= 10^9$ |
| 65 | +- $1 <= target <= 10^9$ |
| 66 | + |
| 67 | +## Implementation |
| 68 | + |
| 69 | +```python |
| 70 | +import numpy as np |
| 71 | + |
| 72 | +def fractal_search(search_space, target): |
| 73 | + def recursive_search(subspace, depth): |
| 74 | + if len(subspace) == 0: |
| 75 | + return -1 |
| 76 | + |
| 77 | + mid_index = len(subspace) // 2 |
| 78 | + mid_value = subspace[mid_index] |
| 79 | + |
| 80 | + if mid_value == target: |
| 81 | + return mid_index |
| 82 | + |
| 83 | + if target < mid_value: |
| 84 | + return recursive_search(subspace[:mid_index], depth + 1) |
| 85 | + else: |
| 86 | + result = recursive_search(subspace[mid_index + 1:], depth + 1) |
| 87 | + return mid_index + 1 + result if result != -1 else -1 |
| 88 | + |
| 89 | + return recursive_search(search_space, 0) |
| 90 | + |
| 91 | +# Example usage: |
| 92 | +search_space = [1, 3, 5, 7, 9] |
| 93 | +target = 5 |
| 94 | +print(fractal_search(search_space, target)) # Output: 2 |
| 95 | +``` |
| 96 | + |
| 97 | +```cpp |
| 98 | +#include <iostream> |
| 99 | +#include <vector> |
| 100 | + |
| 101 | +int fractal_search(const std::vector<int>& search_space, int target) { |
| 102 | + int recursive_search(const std::vector<int>& subspace, int depth) { |
| 103 | + if (subspace.empty()) { |
| 104 | + return -1; |
| 105 | + } |
| 106 | + |
| 107 | + int mid_index = subspace.size() / 2; |
| 108 | + int mid_value = subspace[mid_index]; |
| 109 | + |
| 110 | + if (mid_value == target) { |
| 111 | + return mid_index; |
| 112 | + } |
| 113 | + |
| 114 | + if (target < mid_value) { |
| 115 | + return recursive_search({subspace.begin(), subspace.begin() + mid_index}, depth + 1); |
| 116 | + } else { |
| 117 | + int result = recursive_search({subspace.begin() + mid_index + 1, subspace.end()}, depth + 1); |
| 118 | + return result != -1 ? mid_index + 1 + result : -1; |
| 119 | + } |
| 120 | + } |
| 121 | + |
| 122 | + return recursive_search(search_space, 0); |
| 123 | +} |
| 124 | + |
| 125 | +// Example usage: |
| 126 | +int main() { |
| 127 | + std::vector<int> search_space = {1, 3, 5, 7, 9}; |
| 128 | + int target = 5; |
| 129 | + std::cout << fractal_search(search_space, target) << std::endl; // Output: 2 |
| 130 | + return 0; |
| 131 | +} |
| 132 | +``` |
| 133 | +
|
| 134 | +```java |
| 135 | +import java.util.List; |
| 136 | +
|
| 137 | +public class FractalSearch { |
| 138 | + public static int fractalSearch(List<Integer> search_space, int target) { |
| 139 | + int recursiveSearch(List<Integer> subspace, int depth) { |
| 140 | + if (subspace.isEmpty()) { |
| 141 | + return -1; |
| 142 | + } |
| 143 | + |
| 144 | + int midIndex = subspace.size() / 2; |
| 145 | + int midValue = subspace.get(midIndex); |
| 146 | + |
| 147 | + if (midValue == target) { |
| 148 | + return midIndex; |
| 149 | + } |
| 150 | + |
| 151 | + if (target < midValue) { |
| 152 | + return recursiveSearch(subspace.subList(0, midIndex), depth + 1); |
| 153 | + } else { |
| 154 | + int result = recursiveSearch(subspace.subList(midIndex + 1, subspace.size()), depth + 1); |
| 155 | + return result != -1 ? midIndex + 1 + result : -1; |
| 156 | + } |
| 157 | + } |
| 158 | + |
| 159 | + return recursiveSearch(search_space, 0); |
| 160 | + } |
| 161 | +
|
| 162 | + public static void main(String[] args) { |
| 163 | + List<Integer> search_space = List.of(1, 3, 5, 7, 9); |
| 164 | + int target = 5; |
| 165 | + System.out.println(fractalSearch(search_space, target)); // Output: 2 |
| 166 | + } |
| 167 | +} |
| 168 | +``` |
| 169 | + |
| 170 | +```javascript |
| 171 | +function fractalSearch(search_space, target) { |
| 172 | + function recursiveSearch(subspace, depth) { |
| 173 | + if (subspace.length === 0) { |
| 174 | + return -1; |
| 175 | + } |
| 176 | + |
| 177 | + const midIndex = Math.floor(subspace.length / 2); |
| 178 | + const midValue = subspace[midIndex]; |
| 179 | + |
| 180 | + if (midValue === target) { |
| 181 | + return midIndex; |
| 182 | + } |
| 183 | + |
| 184 | + if (target < midValue) { |
| 185 | + return recursiveSearch(subspace.slice(0, midIndex), depth + 1); |
| 186 | + } else { |
| 187 | + const result = recursiveSearch(subspace.slice(midIndex + 1), depth + 1); |
| 188 | + return result !== -1 ? midIndex + 1 + result : -1; |
| 189 | + } |
| 190 | + } |
| 191 | + |
| 192 | + return recursiveSearch(search_space, 0); |
| 193 | +} |
| 194 | + |
| 195 | +// Example usage: |
| 196 | +const search_space = [1, 3, 5, 7, 9]; |
| 197 | +const target = 5; |
| 198 | +console.log(fractalSearch(search_space, target)); // Output: 2 |
| 199 | +``` |
| 200 | + |
| 201 | +# Complexity Analysis |
| 202 | +### Time Complexity: $O(\log n)$, where $n$ is the number of elements in the search space. The recursive division reduces the search space exponentially. |
| 203 | +### Space Complexity: $O(n)$, due to the additional space required for recursive function calls and subspaces. |
| 204 | +# Advantages and Disadvantages |
| 205 | +## Advantages: |
| 206 | + |
| 207 | +Efficient for large and complex search spaces due to the recursive division. |
| 208 | +Exploits the self-similarity of fractals, making it suitable for certain types of data structures. |
| 209 | +## Disadvantages: |
| 210 | + |
| 211 | +More complex to implement compared to traditional search algorithms. |
| 212 | +Performance may vary depending on the nature of the search space and fractal pattern used. |
| 213 | +### References |
| 214 | +Wikipedia: Fractal |
| 215 | +Research Paper: Fractal Search Algorithm |
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