알고리즘 대비

문법

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예외 처리

try:

except:"

Operation

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print( 10 / 2 )
# 5.0

print( 10 // 2)
# 5

print( 10 % 3 )
# 나머지 1

print( 2 ** 3 )
# 2^3 = 8

print( 2 * 3 )
#  6

배열

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a =[1,2,3,4]

print(a[1:])
# [2,3,4]

print(a[1:2])
# [2]

print(a[0:])
# []

print(a[-1:])
# [4]

print(a[:-1])
# [1, 2, 3]

[ 1, 2, 3, 4, 5 ]

[ -5, -4, -3, -2, -1 ]

 

import math

a = [ i for i in range(10)]
print(a)
# [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ]

a = [ i for i in range(1,3)]
print(a)
# [ 1, 2 ]

a = [ False ] * 2
print(a)
# [False, False]

a = [ [] for _ in range(2)]
print(a)
# [[], []]

a = [ [math.inf] for _ in range(3)]
print(a)
# [[inf], [inf], [inf]]

a = [ [3] * 2 for _ in range(4)]
print(a)
# [[3, 3], [3, 3], [3, 3], [3, 3]]

for i in range(a,b,c) 

a: 

- default: 0

- a에서 부터 b-1 까지

c: 

- default: 1

- c 값 만큼 움직인다.

 

a = [1,23,4]

for inx, value in enumerate(a):
    print(inx,value)
    
# 0 1
# 1 23
# 2 4

 

조건문

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str = "light"
if "k" in str:
    print("!")
else:
    print("!!")
    
# !!

arry = [1,2,3]
if 1 in arry:
    print("in array")
else:
    print("not in array")
    
# in array

 

Deque, Heap, Dict, Set

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Deque

from collections import deque

que = deque()
que.append(1)
que.append(2)
print(que)
# deque([1, 2])

a = que.index(1)
print(a)
# 0

if 2 in que:
    print("in")
else:
    print("not in")
    
# in

Heap ( 우선 순위 q ) => 효율성 할때 사용

import heapq

heap= []

heapq.heappush(heap,4)
heapq.heappush(heap,1)
heapq.heappush(heap,10)

a = heapq.heappop(heap)
print(a)
# 1

a = heapq.heappop(heap)
print(a)
# 4

a = heapq.heappop(heap)
print(a)
# 10

Input

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