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Showing posts from February, 2016

### Insertion Sort in Python.

Insertion sort is somehow difficult when I wrote code from only logic images

this is not optimized Insertion sort
I will optimize and update sort code

arr = [5,2,3,7,1,4] 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 : breakinsertionSort(arr) print(arr)

### bubble Sort in Python

this is second weeks in algorithm study,I want learn python and study basic algorithm.this time I studied Bubble sort.this time complexity is always O(N^2).next time I will rewrite optimized Bubble sort arr = [5, 1, 4, 2, 8] def swap(arr, a, b): temp = arr[a]; arr[a] = arr[b]; arr[b] = temp; def bubblesort(arr): for i in range(len(arr)) : print( str(i+1) + " 번재 passing"); for j in range(len(arr)-1): if arr[j] > arr[j+1] : swap(arr, j, j+1); print(arr) bubblesort( arr); print("result : ") print(arr)

### This is a selection sort algorithm

This time I attended algorithm study group using geeksforgeeks hompage.this is just start and review algorithm basic.I hope to study this steadily .If you have question about selection sort. reply~!time complexity O(n2)arr = [5,2,3,7,1,4] def selectionSort(arr): for i in range(len(arr)-1): print(i) minimum = arr[i] for j in range(i+1, len(arr)): if arr[j] < minimum: minimum = arr[j] swap(arr, i, j) print(arr); def swap(arr, i, j): temp = arr[i] arr[i] = arr[j] arr[j] = temp def selectionSortOnlyOneSwap(arr): for i in range(len(arr)-1): print(i) minimum = arr[i] minposition = i for j in range(i+1, len(arr)): if arr[j] < minimum: minimum = arr[j] minposition = j if minposition != i: swap(arr, i, minposition) print(arr) selectionSort(arr) print(arr) print("only one t…

### Problem 539 Odd Elimination~!

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나는 나만의 계산 방법으로 풀었는데..  실제 답을 보니깐 수학 전개식을 이용해서 작성한 사람들이 있었다. 대단한것 같다.  이번에 이 문제를 풀기위해서 15일을 투자를 했다. 머 하루종일 손을 잡은것은 아니데.. 하루에 1-2시간씩은 생각하고 코딩하고 이런식으로 작업을 했다.
어쨋든 풀고나니 희열도 있고, 자신감도 얻고, 얻는 효과가 많이 있는것 같다. 풀이 방법에 대해서 알고싶은분은 댓글달아주세요.