137 lines
2.3 KiB
Markdown
137 lines
2.3 KiB
Markdown
# String Exercises
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## Exercise 1.1 (Search)
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```python
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def search(x: str, s:str) -> int:
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"""
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Function that counts the number
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of occurences of a given character
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in a string
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@params x (str): the keyword
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@params s (str): the string
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@return: (int): the number of occurences
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"""
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i = 0
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pos = -1
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while i < len(s) and pos == -1:
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if s[i] == c:
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pos = i
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i += 1
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return pos
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def search2(s: str, x: str) -> int:
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"""
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Function that counts the number
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of occurences of a given character
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in a string
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@params x (str): the string
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@return: (int): the occurence where is appear
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"""
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i = 1
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n = len(s)
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for i in range(n):
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if s[i] == x:
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return i
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return -1
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```
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## Exercise 1.2 (Palindrome)
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```python
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def palindrome(sentence: str) -> bool:
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"""
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Function that check if a number is a palindrome
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@params sentence(str): the sentence to check
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@return (bool): Either a palindrome or not
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"""
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newSentence = ""
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oldSentence = ""
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for element in sentence:
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if element != " ":
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newSentence = element + newSentence
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for element in sentence:
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if element != " ":
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oldSentence += element
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if newSentence == oldSentence:
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return True
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else:
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return False
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def ispalind(s):
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start = 0
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end = len(s)-1
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while start<end and s[start]==s[end]:
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end -= 1
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start += 1
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if s[start] == " ":
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start += 1
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if s[end] == " ":
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end -= 1
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return start >= end
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```
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## Exercise 2.1 (conversions)
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1)
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```python
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def dec_to_bin(n, p):
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s = ""
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while n > 0:
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s = str(n%2) +s
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n = n//2
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for i in range(p-len(s)):
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s = "0" + s
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return s
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def integer_to_twoscomp(n, p):
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if n < 0:
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n = power(2, p) + n
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return dec_to_bin(n, p)
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def bin_to_dec(s):
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n = 0
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for b in s:
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n = n * 2 + int(b)
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return b
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```
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2)
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```python
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def power(x, p):
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res = 1
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while p > 0:
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res *= x
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p -= 1
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return res
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def int_to_twoscomp(n, p):
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if n < 0:
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n = power(2,p) + n
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return dec_to_bin(n,p)
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```
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## Exercise 2.2 (Frequency)
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```python
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def frequency(s: string):
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count = 0
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countInter = 0
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elementMax = ""
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index = 0
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foreach elem in s:
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for i in range(index, lenght(s)):
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if s[i] == elem:
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countInter += 1
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if countInter > count:
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count = countInter
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elementMax = elem
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index += 1
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return (cout, elementMax)
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```
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