Solution of Lucky Numbers is added

dsa-solutions/gfg-solutions/Easy problems/Lucky-Numbers.md

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+---
+id: nth-fibonacci-number
+title: Nth Fibonacci Number
+sidebar_label: Nth Fibonacci Number
+tags:
+  - Easy
+  - Dynamic Programming
+  - Math
+description: "This tutorial covers the solution to the Nth Fibonacci Number problem from the GeeksforGeeks."
+---
+## Problem Description
+
+Lucky numbers are subset of integers. Rather than going into much theory, let us see the process of arriving at lucky numbers,
+Take the set of integers
+`1`, `2`, `3`, `4`, `5`, `6`, `7`, `8`, `9`, `10`, `11`, `12`, `13`, `14`, `15`, `16`, `17`, `18`, `19`,……
+First, delete every second number, we get following reduced set.
+`1`, `3`, `5`, `7`, `9`, `11`, `13`, `15`, `17`, `19`,…………
+Now, delete every third number, we get
+`1`, `3`, `7`, `9`, `13`, `15`, `19`,….….
+Continue this process indefinitely……
+Any number that does NOT get deleted due to above process is called “lucky”.
+
+You are given a number N, you need to tell whether the number is lucky or not. If the number is lucky return 1 otherwise 0.
+
+## Examples
+
+**Example 1:**
+
+```
+Input:
+N = 5
+Output: 0
+Explanation: 5 is not a lucky number 
+as it gets deleted in the second 
+iteration.
+```
+
+**Example 2:**
+
+```
+Input:
+N = 19
+Output: 1
+Explanation: 19 is a lucky number because 
+it does not get deleted throughout the process.
+```
+
+## Your Task
+
+You don't need to read input or print anything. You only need to complete the function isLucky() that takes N as parameter and returns either False if the N is not lucky else True.
+
+Expected Time Complexity: $O(sqrt(n))$
+
+Expected Auxiliary Space: $O(1)$ for iterative approach.
+
+## Constraints
+
+* `1 ≤ n ≤ 10^5`
+
+## Problem Explanation
+
+Lucky numbers are subset of integers. Rather than going into much theory, let us see the process of arriving at lucky numbers,
+Take the set of integers
+`1`, `2`, `3`, `4`, `5`, `6`, `7`, `8`, `9`, `10`, `11`, `12`, `13`, `14`, `15`, `16`, `17`, `18`, `19`,……
+First, delete every second number, we get following reduced set.
+`1`, `3`, `5`, `7`, `9`, `11`, `13`, `15`, `17`, `19`,…………
+Now, delete every third number, we get
+`1`, `3`, `7`, `9`, `13`, `15`, `19`,….….
+Continue this process indefinitely……
+Any number that does NOT get deleted due to above process is called “lucky”.
+
+You are given a number N, you need to tell whether the number is lucky or not. If the number is lucky return 1 otherwise 0.
+
+## Code Implementation
+
+<Tabs>
+  <TabItem value="Python" label="Python" default>
+  <SolutionAuthor name="@Ishitamukherjee2004"/>
+
+  ```py
+  def is_lucky(N):
+    lucky_numbers = list(range(1, N + 1))
+    delete_step = 2
+    while delete_step <= len(lucky_numbers):
+        lucky_numbers = [num for i, num in enumerate(lucky_numbers) if (i + 1) % delete_step != 0]
+        delete_step += 1
+    return 1 if N in lucky_numbers else 0
+
+  ```
+
+  </TabItem>
+  <TabItem value="C++" label="C++">
+  <SolutionAuthor name="@Ishitamukherjee2004"/>
+
+  ```cpp
+  int isLucky(int N) {
+    vector<int> luckyNumbers;
+    for (int i = 1; i <= N; i++) {
+        luckyNumbers.push_back(i);
+    }
+    int deleteStep = 2;
+    while (deleteStep <= luckyNumbers.size()) {
+        for (int i = deleteStep - 1; i < luckyNumbers.size(); i += deleteStep) {
+            luckyNumbers.erase(luckyNumbers.begin() + i);
+        }
+        deleteStep++;
+    }
+    for (int num : luckyNumbers) {
+        if (num == N) {
+            return 1;
+        }
+    }
+    return 0;
+}
+
+  ```
+
+  </TabItem>
+
+  <TabItem value="Javascript" label="Javascript" default>
+  <SolutionAuthor name="@Ishitamukherjee2004"/>
+
+  ```javascript
+function isLucky(N) {
+    let luckyNumbers = Array.from({ length: N }, (_, i) => i + 1);
+    let deleteStep = 2;
+    while (deleteStep <= luckyNumbers.length) {
+        luckyNumbers = luckyNumbers.filter((_, i) => (i + 1) % deleteStep !== 0);
+        deleteStep++;
+    }
+    return luckyNumbers.includes(N) ? 1 : 0;
+}
+
+
+  ```
+
+  </TabItem>
+
+  <TabItem value="Typescript" label="Typescript" default>
+  <SolutionAuthor name="@Ishitamukherjee2004"/>
+
+  ```typescript
+function isLucky(N) {
+    let luckyNumbers = Array.from({ length: N }, (_, i) => i + 1);
+    let deleteStep = 2;
+    while (deleteStep <= luckyNumbers.length) {
+        luckyNumbers = luckyNumbers.filter((_, i) => (i + 1) % deleteStep !== 0);
+        deleteStep++;
+    }
+    return luckyNumbers.includes(N) ? 1 : 0;
+}
+
+
+  ```
+
+  </TabItem>
+
+  <TabItem value="Java" label="Java" default>
+  <SolutionAuthor name="@Ishitamukherjee2004"/>
+
+  ```java
+public int isLucky(int N) {
+    List<Integer> luckyNumbers = new ArrayList<>();
+    for (int i = 1; i <= N; i++) {
+        luckyNumbers.add(i);
+    }
+    int deleteStep = 2;
+    while (deleteStep <= luckyNumbers.size()) {
+        for (int i = deleteStep - 1; i < luckyNumbers.size(); i += deleteStep) {
+            luckyNumbers.remove(i);
+        }
+        deleteStep++;
+    }
+    for (int num : luckyNumbers) {
+        if (num == N) {
+            return 1;
+        }
+    }
+    return 0;
+}
+
+
+  ```
+
+  </TabItem>
+</Tabs>
+
+
+## Time Complexity
+
+* The iterative approach has a time complexity of $O(n^2)$.
+
+## Space Complexity
+
+* The space complexity is $O(n)$ since we are using only a fixed amount of extra space.