### 하늘을 날다~ 쿼드콥터 (1)

갑자기 하늘을 날아보고 싶다는 생각이 들었다. 과거 라이트형제은 날아보고 싶다는 생각에 비행기를 만들었을것이다. 나는 아두노이로 쿼드콥터를 만들어봐야겠다. 아두노이도 없고 부품도 없고 아무것도 없다. 부품도 사고 이것저것 사야할것 같다. 오늘부터 쿼드콥터를 만드는거 도전한다. 제발 만들다가 그만두지 말기를...

### codefights smooth sailing ( CommonCharacterCount)

https://codefights.com/arcade/intro/level-3/JKKuHJknZNj4YGL32publicstaticintcommonCharacterCount(String s1, String s2) { int sum = 0; char[] as= s1.toCharArray(); char[] bs= s2.toCharArray(); int[] ias = newint[126]; int[] ibs = newint[126]; for (int i = 0; i < as.length; i++) { ias[(int)as[i]]++; } for (int i = 0; i < bs.length; i++) { ibs[(int)bs[i]]++; } for (int i = 0; i < ibs.length; i++) { sum += Math.min(ias[i], ibs[i]); } return sum; }

Given two strings, find the number of common characters between them. Example For s1 = "aabcc" and s2 = "adcaa", the output should be
commonCharacterCount(s1, s2) = 3. Strings have 3 common characters - 2 "a"s and 1 "c". Input/Output [time limit] 3000ms (java)[input] string s1 A string consisting of lowercase latin letters a-z. Guaranteed constraints:
1 ≤ s1.length ≤ 15. [input] string s2 A string consisting of lowercase latin letters a-z. Guaranteed constr…

### cassandra nodetool troubleshooting

./nodetool -h localhost ring

if you can see this line

Failed to connect to '127.0.0.1:7199': Connection refused

change "cassandra-env.sh"

JVM_OPTS="\$JVM_OPTS -Djava.rmi.server.hostname=<hostname>"

### Bucket Sort in python

I make buckets as many as size of arr
and put data.

arr = [0.897, 0.565, 0.656, 0.1234, 0.665, 0.3434] def bucketSort(arr, size): buckets = [[] for i in range(size)] # put arr in bucket for i in range(len(arr)): num = size*arr[i] buckets[int(num)].append(arr[i]) output = [] # use insertion sort for i in range(len(buckets)): insertionSort(buckets[i]) # concat all data for i in range(len(buckets)): while len(buckets[i]) > 0: output.append(buckets[i].pop(0)) return output def swap(arr, i, j): temp = arr[i] arr[i] = arr[j] arr[j] = temp def insertionSort(arr): for i in range(1, len(arr)): index= i print("index : " + str(i)) while index!=0: if arr[index] < arr[index-1]: temp = arr[index] arr[index]= arr[index-1] arr[index-1] = temp index = index-1print(arr) else …