- DONE Ardour
- 怎么录制
- Ardour vs. audacity
-
- Leetcode - Happy Number
collapsed:: true
- Times:
- Time when completed: 12:36
- Time taken to complete: I forgot, very quick I suppose
- Revisions:
- Tags:
- Algorithms: #Floyd_s_cycle_finding_algorithm
- Difficulty: #difficulty_easy
- Platforms: #leetcode
- Links:
- [link to the problem](https://leetcode.com/problems/happy-number/description/)
- Problem:
- Write an algorithm to determine if a number `n` is happy.
A **happy number** is a number defined by the following process:
- Starting with any positive integer, replace the number by the sum of the squares of its digits.
- Repeat the process until the number equals 1 (where it will stay), or it **loops endlessly in a cycle** which does not include 1.
- Those numbers for which this process **ends in 1** are happy.
Return `true` _if_ `n` _is a happy number, and_ `false` _if not_.
- Examples:
- ```
Example 1:
Input: n = 19
Output: true
Explanation:
12 + 92 = 82
82 + 22 = 68
62 + 82 = 100
12 + 02 + 02 = 1
Example 2:
Input: n = 2
Output: false
```
- Constraints:
- `1 <= n <= 231 - 1`
- Thoughts:
- Intuition:
- It loops endlessly in a cycle, which means we need to use a cycle detection algorithm, which happens to be the [[Floyd's Cycle Finding Algorithm]].
- Approach:
- Use the Floyd's cycle finding algorithm, with two variables
- when fast == slow, cycle is found
- detect if fast is 1, and return values
- Solution:
- Code
- ```java
class Solution {
private int progress(int n) {
int sum = 0;
while (n > 0) {
sum += (n % 10) * (n % 10);
n /= 10;
}
return sum;
}
public boolean isHappy(int n) {
// loop detection
int slow = progress(n);
int fast = progress(slow);
while (slow != fast) {
slow = progress(slow);
fast = progress(progress(fast));
}
return (fast == 1);
}
}
```
-
- Daily reflection [[Daily reflections]]
collapsed:: true
- What I've done
- 写学交论文
- 音乐 improvising
- I met someone, she's gorgeous
- What I've thought #thoughts
- Improvisation is fun :)
- I think I fall in love with someone, I have a strong feeling when she is nearby, and dopamine burst out whenever I talk to her. I don't know if she feel the same (I think to some extent she does. I don't really know, I just follow the flow and enjoy every moment of that). ~~aaand also I erected a lot~~
- Mood
- Generally excited, but sometimes exhausted from these happy feelings, I deserve a good sleep.
-
- Todo
- DONE Edx 写一篇 blues
:LOGBOOK:
CLOCK: [2023-04-07 Fri 14:36:18]--[2023-04-07 Fri 16:50:36] => 02:14:18
:END:
- DONE 概率论作业
:LOGBOOK:
CLOCK: [2023-04-07 Fri 17:31:14]--[2023-04-07 Fri 21:19:06] => 03:47:52
:END:
- DONE 22, 23, 24, 25, 26, 27, 29
- DONE 58, 59
-
- 乐理学习 #music
- LATER 每天学 15 分钟 Open Music Theory [上次学到的地方](https://viva.pressbooks.pub/openmusictheory/chapter/aspn/)
SCHEDULED: <2023-06-20 Tue .+1d>
:LOGBOOK:
- State "DONE" from "LATER" [2023-04-07 Fri 16:50]
- State "DONE" from "LATER" [2023-04-07 Fri 16:52]
* State "DONE" from "LATER" [2023-04-10 Mon 22:49]
* State "DONE" from "LATER" [2023-04-11 Tue 23:35]
CLOCK: [2023-04-12 Wed 09:16:56]--[2023-04-12 Wed 09:44:02] => 00:27:06
* State "DONE" from "LATER" [2023-04-12 Wed 09:44]
* State "DONE" from "LATER" [2023-04-18 Tue 23:31]
* State "DONE" from "LATER" [2023-04-21 Fri 09:30]
CLOCK: [2023-04-23 Sun 15:18:42]--[2023-04-23 Sun 15:18:43] => 00:00:01
* State "DONE" from "NOW" [2023-04-23 Sun 15:18]
* State "DONE" from "LATER" [2023-04-26 Wed 22:31]
* State "DONE" from "LATER" [2023-05-08 Mon 20:47]
CLOCK: [2023-05-09 Tue 09:52:58]--[2023-05-09 Tue 10:01:36] => 00:08:38
* State "DONE" from "NOW" [2023-05-09 Tue 10:01]
CLOCK: [2023-05-09 Tue 10:11:30]--[2023-05-09 Tue 10:11:31] => 00:00:01
CLOCK: [2023-05-11 Thu 10:14:15]--[2023-05-11 Thu 11:16:14] => 01:01:59
* State "DONE" from "NOW" [2023-05-11 Thu 11:16]
* State "DONE" from "LATER" [2023-05-15 Mon 16:23]
:END:
- LATER 每天 5 分钟 Ear training [Teoria](https://www.teoria.com/en/exercises/)
SCHEDULED: <2023-06-20 Tue .+1d>
:LOGBOOK:
- State "DONE" from "LATER" [2023-04-07 Fri 23:31]
* State "DONE" from "LATER" [2023-04-11 Tue 16:41]
* State "DONE" from "LATER" [2023-04-12 Wed 15:07]
CLOCK: [2023-04-21 Fri 14:41:07]--[2023-04-21 Fri 14:41:09] => 00:00:02
* State "DONE" from "LATER" [2023-04-25 Tue 11:33]
* State "DONE" from "LATER" [2023-04-26 Wed 22:31]
* State "DONE" from "LATER" [2023-05-08 Mon 20:48]
CLOCK: [2023-05-09 Tue 10:01:48]--[2023-05-09 Tue 10:10:01] => 00:08:13
* State "DONE" from "LATER" [2023-05-09 Tue 10:10]
* State "DONE" from "LATER" [2023-05-11 Thu 20:06]
:END: