Algorithms

GMM for EM-algorithm

45 minute read

unsupervised problem for EM algorithm, especially gaussian mixture model.

Heap and Priority Queue Analysis and Practice using python

50 minute read

How to use and implement heap and priority queue using python

Dijkstra Algorithm in Python

41 minute read

Implementaiton and Description of Dijkstra Algorithm

Floyd Warshall Algorithm in Python

37 minute read

All pair shortest paths algorithm

Bellman-Ford and DAG Algorithms in Python

28 minute read

Single source shortest path Algorithm

나무 재테크

15 minute read

주어진 조건에 따라 시뮬레이션 하는 문제, 적절한 자료구조 사용

인구이동

17 minute read

Union Find을 사용하여 시뮬레이션 해보는 알고리즘

낚시왕

26 minute read

상어 클래스를 만들고, 이를 배열에 넣어 다루는 연습, 시뮬레이션

드래곤 커브

23 minute read

규칙성을 찾고 이를 바탕으로 DFS 연습

치킨배달

4 minute read

조합에 대한 경우의 수 탐색하는 연습

아기상어

15 minute read

우선순위에 따른 BFS 연습을 하기 좋은 문제

이차원배열과 연산

15 minute read

행 연산과, 열 연산 연습

감시

42 minute read

DFS, backtracking, or pruning practice

사다리조작

72 minute read

DFS, backtracking, or pruning practice

스타트와 링크

20 minute read

팀 나누기, DFS, combination 연습

경사로

11 minute read

simulation practice

톱니바퀴

23 minute read

DFS, rotate practice

How to implement Permutation in python

6 minute read

A practice to implmentation of permutation.

연산자 끼워넣기

5 minute read

DFS practice

바이러스

14 minute read

바이러스의 전파를 막기 위해 DFS를 사용하여 최소화하는 벽을 세워보자

테트로미노

14 minute read

주어진 조건에 맞추어 테트리스를 활용한 문제를 풀어보자

로봇 청소기

33 minute read

주어진 조건에 맞게 구현

퇴사

16 minute read

DFS, DP를 이용하여 문제 풀이 연습

GCD 와 LCD 구하기

2 minute read

최대공약수, 최소공배수를 구해라

시험감독

1 minute read

코딩 테스트 연습

주사위 굴리기

9 minute read

주사위와 회전을 구현해보자.

뱀- 구현능력점검

43 minute read

시뮬레이션을 구현할 수 있나 테스트, queue의 사용연습

2048(Easy)

32 minute read

queue의 사용과 DFS 연습, 삼성 역량 테스트

79.Word Search

49 minute read

Given a 2D board and a word, find if the word exist in the grid: backtracking, pruning practice.

Find Top K sth

17 minute read

sorting and heap usage practice

프로세서 연결하기

31 minute read

삼성sw 역량 테스트 문제. 가능한 프로세서를 모두 연결시키되필요한 최소전선수를 찾아라

구슬탈출2

41 minute read

samsung sw test practice, DFS and BFS practice

1315.Sum of Nodes with Even-Valued Grandparent

8 minute read

practice of DFS

218.The Skyline Problem

9 minute read

Practice of divide and conquer, heap.

Find Prime Factors

3 minute read

how to find prim factors

1319.Number of Operations to Make Network Connected

9 minute read

practice of disjoint set

200.Number of Islands

12 minute read

practice of DFS and union find

1254.Number of Closed Island

16 minute read

2 step of DFS, union find practice

128.Longest Consecutive Sequences

9 minute read

practice of disjoint set

785.Is Graph Bipartite

5 minute read

use DFS or BFS, check if a graph is bipartite or not.

1080.Insufficient Nodes in Root to Leaf Paths

5 minute read

Practice to use DFS

337.House Robber III

10 minute read

practice of DFS

1390.Four Divisors

8 minute read

practice of a mathmatical algorithms

114.Flatten Binary Tree to Linked List

3 minute read

practice of DFS

802.Find Eventual Safe States

8 minute read

practice of DFS, this is an application of detecting cycle.

399.Evalutate Division

15 minute read

make use of graph, and disjoint set to find division rate

979.Distribute Coins in Binary Tree

4 minute read

practice to DFS

Detect Cycle in an Undirected Graph

3 minute read

using disjoint set, easily check if a graph has any cycle.

1302.Deepest Leaves Sum

3 minute read

practice to DFS

105.Construct Binary Tree from Preorder and Inorder Traversal

6 minute read

practice of binary tree traversal

How to implement and visualize Binary Tree

7 minute read

tips for making use of binary tree

959.Regions Cut By Slash

16 minute read

disjoint set, or union find algorithm is utilized.

947.Most Stones Removed with Same Row or Column

23 minute read

union find, disjoint set, dfs are used to solve this problem

How to implement Disjointset or Union Find using python

22 minute read

Let’s learn about disjiont set using python.

315.Count Smaller Numbers After Self

23 minute read

segment Tree, merge sort are utilized.

677.MapSumPairs

3 minute read

Trie datastructure practice

241.Different Ways to Add Parentheses - leetcode

5 minute read

Practice to utilize divide and conquer technique.

676.Magic Dictionary

13 minute read

Trie data structure practice

211.Add and Search Word - Leetcode

17 minute read

Trie datastructure practice.

how to find path on road network

41 minute read

we use dfs and dijkstra and a star algorithm to find ways

1023.Camelcase Matching Leetcode using python

10 minute read

Trie datastructure practice

How to implement Trie and Practice using python

65 minute read

Let’s learn about what is Trie and how to implement.

How to implement SegmentTree and Practice using python

42 minute read

Let’s learn about what is segment tree and how to implement.

Find Maximum Subarray Analysis comparing several algorithms using python

22 minute read

algorithm pratice to find maximum subarray problem.

N-Queens Problem using python

14 minute read

Good Pratice of DFS on 2D grid space.

DFS and BFS

17 minute read

Depth First Search and Bread First Search

973.K Closest Points - Leetcode

9 minute read

Find top K cloest points with origin.

932.Beautiful Array - Leetcode

10 minute read

using divide and conquer, find any beautiful array.

650.2 Keys Keyboard - Leetcode

8 minute read

Find the number of operations to make target string given 2 keys.

417.Pacific Atlantic Water Flow

15 minute read

Check if there are ways to go both Pacific, Atlantic ocean

169.Majority Element - Leetcode

6 minute read

Find Majority Elment in a given array

329.Longest Increasing Path - Leetcode

7 minute read

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72.Edit Distance using python - Leetcode

10 minute read

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932.Beautiful Array - Leetcode

10 minute read

permutate an array to become beautiful array using python

Detect Cycle using topolgoical sort python implementation

18 minute read

detect cycle in a given graph

Course Schedule - leetcode 207 and 210 using python

11 minute read

KEY: using BFS or DFS, detect cycles in a graph

721.Account and Merge

22 minute read

merge emails by finding same account from given input.

851.Loud and Rich using python - Leetcode

17 minute read

find a person who have the least quiet among people who have same, or more money

Binary Search using python

6 minute read

implement binary search recursive and iterative.

Pumping Oil using python

13 minute read

14.LCP using python - Leetcode

17 minute read

find longest common prefix among given words

935.Knight Dialer using python - Leetcode

18 minute read

find distinct ways to press dial pads

Karatsuba Algorithm for Binary Multiplication using python - Divide and Conquer

22 minute read

given two binary values, multiply efficiently.

Frevialds Algorithms for checking Matrix Multiplication randomly

22 minute read

How to check multiplication of given two square matrices.

Append and Delete - hackerrank

3 minute read

make source string to target string using Append and Delete operations

Rod Cutting Problem - Dynamic Programming

20 minute read

Rod Cutting Problem

Climing the Leaderboard - hackerrank

21 minute read

find ordered statstics from a user’s scores

9480.민정이와 광직이의 알파벳 공부

40 minute read

enumerate all cases, Target Sum

Counting Inversions using Divide and Conquer

18 minute read

algorithm practice, count inversions in a given array.

2D Cloest Pair python (Divide and Conquer)

43 minute read

using Divide and Conquer, solve 2D cloest pair problem

Quicksort with median of medians algorithm(efficient sorting)

32 minute read

Let’s learning about an algorithm that finds k-th elemen using median of medians to ensure linear time. And use it to quick sort algorithm.

735.Asteroid Collision

13 minute read

stack practice - how to use stack and how to think the use.

948.Bag Of Tokens

17 minute read

solve this problem using python and c++

129.Sum Root to Leaf Numbers

9 minute read

Find the total sum of all root-to-leaf numbers.

934.Shortest Bridge

13 minute read

Find shortest bridge between two islands

695.Max Area of Island

9 minute read

Given many islands, we want to find maximum size of island.

714.Stock Problem

13 minute read

sell stock with transaction fee

55.Jump Game

11 minute read

Determine if you are able to reach the last index.

Maximum Subarray Problem

8 minute read

Maximum Subarray Problem step by step

APM part2

65 minute read

Advanced Programming Methologies part2

APM part1

142 minute read

Advanced Programming Methologies part1

494.Target Sum

15 minute read

algoritm practice