|
1 |
| ---- |
2 |
| -id: lucky-number |
3 |
| -title: Nth Fibonacci Number |
4 |
| -sidebar_label: Nth Fibonacci Number |
5 |
| -tags: |
6 |
| - - Easy |
7 |
| - - Dynamic Programming |
8 |
| - - Math |
9 |
| -description: "This tutorial covers the solution to the Nth Fibonacci Number problem from the GeeksforGeeks." |
10 |
| ---- |
11 |
| -## Problem Description |
12 |
| - |
13 |
| -Lucky numbers are subset of integers. Rather than going into much theory, let us see the process of arriving at lucky numbers, |
14 |
| -Take the set of integers |
15 |
| -`1`, `2`, `3`, `4`, `5`, `6`, `7`, `8`, `9`, `10`, `11`, `12`, `13`, `14`, `15`, `16`, `17`, `18`, `19`,…… |
16 |
| -First, delete every second number, we get following reduced set. |
17 |
| -`1`, `3`, `5`, `7`, `9`, `11`, `13`, `15`, `17`, `19`,………… |
18 |
| -Now, delete every third number, we get |
19 |
| -`1`, `3`, `7`, `9`, `13`, `15`, `19`,….…. |
20 |
| -Continue this process indefinitely…… |
21 |
| -Any number that does NOT get deleted due to above process is called “lucky”. |
22 |
| - |
23 |
| -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. |
24 |
| - |
25 |
| -## Examples |
26 |
| - |
27 |
| -**Example 1:** |
28 |
| - |
29 |
| -``` |
30 |
| -Input: |
31 |
| -N = 5 |
32 |
| -Output: 0 |
33 |
| -Explanation: 5 is not a lucky number |
34 |
| -as it gets deleted in the second |
35 |
| -iteration. |
36 |
| -``` |
37 |
| - |
38 |
| -**Example 2:** |
39 |
| - |
40 |
| -``` |
41 |
| -Input: |
42 |
| -N = 19 |
43 |
| -Output: 1 |
44 |
| -Explanation: 19 is a lucky number because |
45 |
| -it does not get deleted throughout the process. |
46 |
| -``` |
47 |
| - |
48 |
| -## Your Task |
49 |
| - |
50 |
| -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. |
51 |
| - |
52 |
| -Expected Time Complexity: $O(sqrt(n))$ |
53 |
| - |
54 |
| -Expected Auxiliary Space: $O(1)$ for iterative approach. |
55 |
| - |
56 |
| -## Constraints |
57 |
| - |
58 |
| -* `1 ≤ n ≤ 10^5` |
59 |
| - |
60 |
| -## Problem Explanation |
61 |
| - |
62 |
| -Lucky numbers are subset of integers. Rather than going into much theory, let us see the process of arriving at lucky numbers, |
63 |
| -Take the set of integers |
64 |
| -`1`, `2`, `3`, `4`, `5`, `6`, `7`, `8`, `9`, `10`, `11`, `12`, `13`, `14`, `15`, `16`, `17`, `18`, `19`,…… |
65 |
| -First, delete every second number, we get following reduced set. |
66 |
| -`1`, `3`, `5`, `7`, `9`, `11`, `13`, `15`, `17`, `19`,………… |
67 |
| -Now, delete every third number, we get |
68 |
| -`1`, `3`, `7`, `9`, `13`, `15`, `19`,….…. |
69 |
| -Continue this process indefinitely…… |
70 |
| -Any number that does NOT get deleted due to above process is called “lucky”. |
71 |
| - |
72 |
| -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. |
73 |
| - |
74 |
| -## Code Implementation |
75 |
| - |
76 |
| -<Tabs> |
77 |
| - <TabItem value="Python" label="Python" default> |
78 |
| - <SolutionAuthor name="@Ishitamukherjee2004"/> |
79 |
| - |
80 |
| - ```py |
81 |
| - def is_lucky(N): |
82 |
| - lucky_numbers = list(range(1, N + 1)) |
83 |
| - delete_step = 2 |
84 |
| - while delete_step <= len(lucky_numbers): |
85 |
| - lucky_numbers = [num for i, num in enumerate(lucky_numbers) if (i + 1) % delete_step != 0] |
86 |
| - delete_step += 1 |
87 |
| - return 1 if N in lucky_numbers else 0 |
88 |
| - |
89 |
| - ``` |
90 |
| - |
91 |
| - </TabItem> |
92 |
| - <TabItem value="C++" label="C++"> |
93 |
| - <SolutionAuthor name="@Ishitamukherjee2004"/> |
94 |
| - |
95 |
| - ```cpp |
96 |
| - int isLucky(int N) { |
97 |
| - vector<int> luckyNumbers; |
98 |
| - for (int i = 1; i <= N; i++) { |
99 |
| - luckyNumbers.push_back(i); |
100 |
| - } |
101 |
| - int deleteStep = 2; |
102 |
| - while (deleteStep <= luckyNumbers.size()) { |
103 |
| - for (int i = deleteStep - 1; i < luckyNumbers.size(); i += deleteStep) { |
104 |
| - luckyNumbers.erase(luckyNumbers.begin() + i); |
105 |
| - } |
106 |
| - deleteStep++; |
107 |
| - } |
108 |
| - for (int num : luckyNumbers) { |
109 |
| - if (num == N) { |
110 |
| - return 1; |
111 |
| - } |
112 |
| - } |
113 |
| - return 0; |
114 |
| -} |
115 |
| - |
116 |
| - ``` |
117 |
| -
|
118 |
| - </TabItem> |
119 |
| -
|
120 |
| - <TabItem value="Javascript" label="Javascript" default> |
121 |
| - <SolutionAuthor name="@Ishitamukherjee2004"/> |
122 |
| -
|
123 |
| - ```javascript |
124 |
| -function isLucky(N) { |
125 |
| - let luckyNumbers = Array.from({ length: N }, (_, i) => i + 1); |
126 |
| - let deleteStep = 2; |
127 |
| - while (deleteStep <= luckyNumbers.length) { |
128 |
| - luckyNumbers = luckyNumbers.filter((_, i) => (i + 1) % deleteStep !== 0); |
129 |
| - deleteStep++; |
130 |
| - } |
131 |
| - return luckyNumbers.includes(N) ? 1 : 0; |
132 |
| -} |
133 |
| -
|
134 |
| -
|
135 |
| - ``` |
136 |
| - |
137 |
| - </TabItem> |
138 |
| - |
139 |
| - <TabItem value="Typescript" label="Typescript" default> |
140 |
| - <SolutionAuthor name="@Ishitamukherjee2004"/> |
141 |
| - |
142 |
| - ```typescript |
143 |
| -function isLucky(N) { |
144 |
| - let luckyNumbers = Array.from({ length: N }, (_, i) => i + 1); |
145 |
| - let deleteStep = 2; |
146 |
| - while (deleteStep <= luckyNumbers.length) { |
147 |
| - luckyNumbers = luckyNumbers.filter((_, i) => (i + 1) % deleteStep !== 0); |
148 |
| - deleteStep++; |
149 |
| - } |
150 |
| - return luckyNumbers.includes(N) ? 1 : 0; |
151 |
| -} |
152 |
| - |
153 |
| - |
154 |
| - ``` |
155 |
| - |
156 |
| - </TabItem> |
157 |
| - |
158 |
| - <TabItem value="Java" label="Java" default> |
159 |
| - <SolutionAuthor name="@Ishitamukherjee2004"/> |
160 |
| - |
161 |
| - ```java |
162 |
| -public int isLucky(int N) { |
163 |
| - List<Integer> luckyNumbers = new ArrayList<>(); |
164 |
| - for (int i = 1; i <= N; i++) { |
165 |
| - luckyNumbers.add(i); |
166 |
| - } |
167 |
| - int deleteStep = 2; |
168 |
| - while (deleteStep <= luckyNumbers.size()) { |
169 |
| - for (int i = deleteStep - 1; i < luckyNumbers.size(); i += deleteStep) { |
170 |
| - luckyNumbers.remove(i); |
171 |
| - } |
172 |
| - deleteStep++; |
173 |
| - } |
174 |
| - for (int num : luckyNumbers) { |
175 |
| - if (num == N) { |
176 |
| - return 1; |
177 |
| - } |
178 |
| - } |
179 |
| - return 0; |
180 |
| -} |
181 |
| - |
182 |
| - |
183 |
| - ``` |
184 |
| - |
185 |
| - </TabItem> |
186 |
| -</Tabs> |
187 |
| - |
188 |
| - |
189 |
| -## Time Complexity |
190 |
| - |
191 |
| -* The iterative approach has a time complexity of $O(n^2)$. |
192 |
| - |
193 |
| -## Space Complexity |
194 |
| - |
195 |
| -* The space complexity is $O(n)$ since we are using only a fixed amount of extra space. |
| 1 | +--- |
| 2 | +id: lucky-number |
| 3 | +title: Nth Fibonacci Number |
| 4 | +sidebar_label: Nth Fibonacci Number |
| 5 | +tags: |
| 6 | + - Easy |
| 7 | + - Dynamic Programming |
| 8 | + - Math |
| 9 | +description: "This tutorial covers the solution to the Nth Fibonacci Number problem from the GeeksforGeeks." |
| 10 | +--- |
| 11 | + |
| 12 | +## Problem Description |
| 13 | + |
| 14 | +Lucky numbers are subset of integers. Rather than going into much theory, let us see the process of arriving at lucky numbers, |
| 15 | +Take the set of integers |
| 16 | +`1`, `2`, `3`, `4`, `5`, `6`, `7`, `8`, `9`, `10`, `11`, `12`, `13`, `14`, `15`, `16`, `17`, `18`, `19`,…… |
| 17 | +First, delete every second number, we get following reduced set. |
| 18 | +`1`, `3`, `5`, `7`, `9`, `11`, `13`, `15`, `17`, `19`,………… |
| 19 | +Now, delete every third number, we get |
| 20 | +`1`, `3`, `7`, `9`, `13`, `15`, `19`,….…. |
| 21 | +Continue this process indefinitely…… |
| 22 | +Any number that does NOT get deleted due to above process is called “lucky”. |
| 23 | + |
| 24 | +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. |
| 25 | + |
| 26 | +## Examples |
| 27 | + |
| 28 | +**Example 1:** |
| 29 | + |
| 30 | +``` |
| 31 | +Input: |
| 32 | +N = 5 |
| 33 | +Output: 0 |
| 34 | +Explanation: 5 is not a lucky number |
| 35 | +as it gets deleted in the second |
| 36 | +iteration. |
| 37 | +``` |
| 38 | + |
| 39 | +**Example 2:** |
| 40 | + |
| 41 | +``` |
| 42 | +Input: |
| 43 | +N = 19 |
| 44 | +Output: 1 |
| 45 | +Explanation: 19 is a lucky number because |
| 46 | +it does not get deleted throughout the process. |
| 47 | +``` |
| 48 | + |
| 49 | +## Your Task |
| 50 | + |
| 51 | +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. |
| 52 | + |
| 53 | +Expected Time Complexity: $O(sqrt(n))$ |
| 54 | + |
| 55 | +Expected Auxiliary Space: $O(1)$ for iterative approach. |
| 56 | + |
| 57 | +## Constraints |
| 58 | + |
| 59 | +- `1 ≤ n ≤ 10^5` |
| 60 | + |
| 61 | +## Problem Explanation |
| 62 | + |
| 63 | +Lucky numbers are subset of integers. Rather than going into much theory, let us see the process of arriving at lucky numbers, |
| 64 | +Take the set of integers |
| 65 | +`1`, `2`, `3`, `4`, `5`, `6`, `7`, `8`, `9`, `10`, `11`, `12`, `13`, `14`, `15`, `16`, `17`, `18`, `19`,…… |
| 66 | +First, delete every second number, we get following reduced set. |
| 67 | +`1`, `3`, `5`, `7`, `9`, `11`, `13`, `15`, `17`, `19`,………… |
| 68 | +Now, delete every third number, we get |
| 69 | +`1`, `3`, `7`, `9`, `13`, `15`, `19`,….…. |
| 70 | +Continue this process indefinitely…… |
| 71 | +Any number that does NOT get deleted due to above process is called “lucky”. |
| 72 | + |
| 73 | +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. |
| 74 | + |
| 75 | +## Code Implementation |
| 76 | + |
| 77 | +<Tabs> |
| 78 | + <TabItem value="Python" label="Python" default> |
| 79 | + <SolutionAuthor name="@Ishitamukherjee2004"/> |
| 80 | + |
| 81 | +```py |
| 82 | +def is_lucky(N): |
| 83 | + lucky_numbers = list(range(1, N + 1)) |
| 84 | + delete_step = 2 |
| 85 | + while delete_step <= len(lucky_numbers): |
| 86 | + lucky_numbers = [num for i, num in enumerate(lucky_numbers) if (i + 1) % delete_step != 0] |
| 87 | + delete_step += 1 |
| 88 | + return 1 if N in lucky_numbers else 0 |
| 89 | + |
| 90 | +``` |
| 91 | + |
| 92 | + </TabItem> |
| 93 | + <TabItem value="C++" label="C++"> |
| 94 | + <SolutionAuthor name="@Ishitamukherjee2004"/> |
| 95 | + |
| 96 | +```cpp |
| 97 | +int isLucky(int N) { |
| 98 | + vector<int> luckyNumbers; |
| 99 | + for (int i = 1; i <= N; i++) { |
| 100 | + luckyNumbers.push_back(i); |
| 101 | + } |
| 102 | + int deleteStep = 2; |
| 103 | + while (deleteStep <= luckyNumbers.size()) { |
| 104 | + for (int i = deleteStep - 1; i < luckyNumbers.size(); i += deleteStep) { |
| 105 | + luckyNumbers.erase(luckyNumbers.begin() + i); |
| 106 | + } |
| 107 | + deleteStep++; |
| 108 | + } |
| 109 | + for (int num : luckyNumbers) { |
| 110 | + if (num == N) { |
| 111 | + return 1; |
| 112 | + } |
| 113 | + } |
| 114 | + return 0; |
| 115 | +} |
| 116 | + |
| 117 | +``` |
| 118 | +
|
| 119 | + </TabItem> |
| 120 | +
|
| 121 | + <TabItem value="Javascript" label="Javascript" default> |
| 122 | + <SolutionAuthor name="@Ishitamukherjee2004"/> |
| 123 | +
|
| 124 | +```javascript |
| 125 | +function isLucky(N) { |
| 126 | + let luckyNumbers = Array.from({ length: N }, (_, i) => i + 1); |
| 127 | + let deleteStep = 2; |
| 128 | + while (deleteStep <= luckyNumbers.length) { |
| 129 | + luckyNumbers = luckyNumbers.filter((_, i) => (i + 1) % deleteStep !== 0); |
| 130 | + deleteStep++; |
| 131 | + } |
| 132 | + return luckyNumbers.includes(N) ? 1 : 0; |
| 133 | +} |
| 134 | +``` |
| 135 | + |
| 136 | + </TabItem> |
| 137 | + |
| 138 | + <TabItem value="Typescript" label="Typescript" default> |
| 139 | + <SolutionAuthor name="@Ishitamukherjee2004"/> |
| 140 | + |
| 141 | +```typescript |
| 142 | +function isLucky(N) { |
| 143 | + let luckyNumbers = Array.from({ length: N }, (_, i) => i + 1); |
| 144 | + let deleteStep = 2; |
| 145 | + while (deleteStep <= luckyNumbers.length) { |
| 146 | + luckyNumbers = luckyNumbers.filter((_, i) => (i + 1) % deleteStep !== 0); |
| 147 | + deleteStep++; |
| 148 | + } |
| 149 | + return luckyNumbers.includes(N) ? 1 : 0; |
| 150 | +} |
| 151 | +``` |
| 152 | + |
| 153 | + </TabItem> |
| 154 | + |
| 155 | + <TabItem value="Java" label="Java" default> |
| 156 | + <SolutionAuthor name="@Ishitamukherjee2004"/> |
| 157 | + |
| 158 | +```java |
| 159 | +public int isLucky(int N) { |
| 160 | + List<Integer> luckyNumbers = new ArrayList<>(); |
| 161 | + for (int i = 1; i <= N; i++) { |
| 162 | + luckyNumbers.add(i); |
| 163 | + } |
| 164 | + int deleteStep = 2; |
| 165 | + while (deleteStep <= luckyNumbers.size()) { |
| 166 | + for (int i = deleteStep - 1; i < luckyNumbers.size(); i += deleteStep) { |
| 167 | + luckyNumbers.remove(i); |
| 168 | + } |
| 169 | + deleteStep++; |
| 170 | + } |
| 171 | + for (int num : luckyNumbers) { |
| 172 | + if (num == N) { |
| 173 | + return 1; |
| 174 | + } |
| 175 | + } |
| 176 | + return 0; |
| 177 | +} |
| 178 | + |
| 179 | + |
| 180 | +``` |
| 181 | + |
| 182 | + </TabItem> |
| 183 | +</Tabs> |
| 184 | + |
| 185 | +## Time Complexity |
| 186 | + |
| 187 | +- The iterative approach has a time complexity of $O(n^2)$. |
| 188 | + |
| 189 | +## Space Complexity |
| 190 | + |
| 191 | +- The space complexity is $O(n)$ since we are using only a fixed amount of extra space. |
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