### Project Euler 387 Harshad Numbers

This is an easy problem.
when we solve problem there are something to be considered.
I will tell you one tip.

1. from small number to Big number
- problem give us find big number for example sum of over 10^14. just find the answer of smaller number ex) 10^3, 10^4 and check your logic if it is working fine.

I solve this problem by using dp.

### 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 …