devbruce

__all__ = ["find", "union", "is_group"]


def find(node: int, parents: dict[int, int]) -> int:
    if parents[node] != node:
        parents[node] = find(parents[node], parents=parents)
    return parents[node]


def union(n1: int, n2: int, parents: dict[int, int]) -> None:

devbruce

"""
- Greatest Common Divisor(최대공약수) by Euclidean algorithm(유클리드 호제법)
> Reference: Wiki(https://namu.wiki/w/%EC%9C%A0%ED%81%B4%EB%A6%AC%EB%93%9C%20%ED%98%B8%EC%A0%9C%EB%B2%95)

- Least Common Multiple(최소공배수): 두 수의 곱 / 최대공약수
"""


__all__ = ['gcd_while', 'gcd_recursive', 'lcm']

devbruce

"""
Additional Info

- 제곱수(1, 4, 9, 16, 25, 100, 121, ...)의 약수의 갯수는 항상 홀수이다.
"""


__all__ = ['get_divisors', 'get_n_divisors']

devbruce

import numpy as np


__all__ = ['get_cos_sim', 'apply_svd']


def get_cos_sim(v1:np.ndarray, v2:np.ndarray) -> np.float64:
    cos_sim = np.dot(v1, v2) / (np.linalg.norm(v1) * np.linalg.norm(v2))
    return cos_sim

devbruce

"""
Good site for sorting algorithm visualization
- https://visualgo.net/en/sorting
"""


__all__ = [
    'bubble_sort', 'insertion_sort', 'selection_sort',
    'quick_sort', 'merge_sort',
]

devbruce

__all__ = ['dfs_recursive']


visited = set()
visited_orders = list()


def dfs_recursive(start_node: str, graph: dict[str, list[str]]) -> None:
    if start_node in visited:
        return

devbruce

"""
* DFS(Depth First Search)
    - Used Data Structure: Stack
    - Time Complexity: O(V+E)
    
* BFS(Breadth First Search)
    - Used Data Structure: Queue
    - Time Complexity: O(V+E)
"""
from collections import deque

devbruce

"""
Binary search must be preconditioned that arr is sorted(desc).
"""


__all__ = ['bin_search', 'binary_search', 'binary_search_recursive', 'binary_search_recursive2']


def bin_search(arr: list[int], target: int) -> int:
    """Ref: https://www.acmicpc.net/blog/view/109

devbruce

import numpy as np


__all__ = ['nms']


def nms(pred_boxes, iou_thr=0.7, eps=1e-6):
    """Non-Maximum Suppression
    
    Args:

devbruce

import cv2
import numpy as np


__all__ = ['letterbox']


def letterbox(img_arr, target_size, boxes=None):
    """Image Letterboxing (or Pillarboxing)