Given a String extract indices of uppercase characters.
Input : test_str = ‘GeeKsFoRGeeks’
Output : [0, 3, 5, 7, 8]
Explanation : Returns indices of uppercase characters.
Input : test_str = ‘GFG’
Output : [0, 1, 2]
Explanation : All are uppercase.
Method #1 : Using list comprehension + range() + isupper()
In this, we iterate through the indices till string length, and check for uppercase character using isupper(), if found, index is recorded.
Python3
# Python3 code to demonstrate working of# Uppercase Indices# Using list comprehension + range() + isupper()# initializing stringtest_str = 'GeeKsFoRGEEks'# printing original stringprint("The original string is : " + str(test_str))# Uppercase check using isupper()res = [idx for idx in range(len(test_str)) if test_str[idx].isupper()]# printing resultprint("Uppercase elements indices : " + str(res)) |
The original string is : GeeKsFoRGEEks Uppercase elements indices : [0, 3, 5, 7, 8, 9, 10]
Time Complexity: O(n)
Auxiliary Space: O(n)
Method #2 : Using enumerate() + isupper()
In this, the indices are captured using enumerate(), and isupper() does task of uppercase check as in above method.
Python3
# Python3 code to demonstrate working of# Uppercase Indices# Using enumerate() + isupper()# initializing stringtest_str = 'GeeKsFoRGEEks'# printing original stringprint("The original string is : " + str(test_str))# Uppercase check using isupper()# enumerate() gets indicesres = [idx for idx, chr in enumerate(test_str) if chr.isupper()]# printing resultprint("Uppercase elements indices : " + str(res)) |
The original string is : GeeKsFoRGEEks Uppercase elements indices : [0, 3, 5, 7, 8, 9, 10]
Time Complexity: O(n)
Auxiliary Space: O(n)
Method #3 : Without isupper() method
Python3
# Python3 code to demonstrate working of# Uppercase Indices# Using list comprehension + range() + isupper()# initializing stringtest_str = 'GeeKsFoRGEEks'upperalphabets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"# printing original stringprint("The original string is : " + str(test_str))res=[]# Uppercase checkfor i in range(0,len(test_str)): if test_str[i] in upperalphabets: res.append(i)# printing resultprint("Uppercase elements indices : " + str(res)) |
The original string is : GeeKsFoRGEEks Uppercase elements indices : [0, 3, 5, 7, 8, 9, 10]
Time Complexity: O(n)
Auxiliary Space: O(n)
Method #4 : Using ord() function
Python3
# Python3 code to demonstrate working of# Uppercase Indices# initializing stringtest_str = 'GeeKsFoRGEEks'# printing original stringprint("The original string is : " + str(test_str))res=[]# Uppercase checkfor i in range(0,len(test_str)): if ord(test_str[i]) in range(65,91): res.append(i)# printing resultprint("Uppercase elements indices : " + str(res)) |
The original string is : GeeKsFoRGEEks Uppercase elements indices : [0, 3, 5, 7, 8, 9, 10]
The Time and Space Complexity for all the methods are the same:
Time Complexity: O(n)
Auxiliary Space: O(n)
Method #4 : Using operator.countOf() method
Python3
# Python3 code to demonstrate working of# Uppercase Indices# Using operator.countOf() methodimport operator as op# initializing stringtest_str = 'GeeKsFoRGEEks'upperalphabets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"# printing original stringprint("The original string is : " + str(test_str))res = []# Uppercase checkfor i in range(0, len(test_str)): if op.countOf(upperalphabets, test_str[i]) > 0: res.append(i)# printing resultprint("Uppercase elements indices : " + str(res)) |
The original string is : GeeKsFoRGEEks Uppercase elements indices : [0, 3, 5, 7, 8, 9, 10]
Time Complexity: O(n)
Auxiliary Space: O(n)
Method#5: Using Recursive method.
Python3
# Python3 code to demonstrate working of# Uppercase Indices# Using recursive methoddef uppercase_indices(string, idx=0, result=None): if result is None: result = [] if idx == len(string): return result if string[idx].isupper(): result.append(idx) return uppercase_indices(string, idx + 1, result)# initializing stringtest_str = 'GeeKsFoRGEEks'# printing original stringprint("The original string is : " + str(test_str))res=uppercase_indices(test_str)# printing resultprint("Uppercase elements indices : " + str(res))#this code contributed by tvsk |
The original string is : GeeKsFoRGEEks Uppercase elements indices : [0, 3, 5, 7, 8, 9, 10]
Time Complexity: O(n)
Auxiliary Space: O(n)
Method#6: Using re and finditer function
Python3
import re# initializing stringtest_str = 'GeeKsFoRGEEks'# printing original stringprint("The original string is : " + str(test_str))# Finding indices of uppercase characters using re.finditerres = [match.start() for match in re.finditer(r'[A-Z]', test_str)]# printing resultprint("Uppercase elements indices : " + str(res))#This code is contributed by Vinay Pinjala. |
The original string is : GeeKsFoRGEEks Uppercase elements indices : [0, 3, 5, 7, 8, 9, 10]
Time Complexity: O(n)
Auxiliary Space: O(n)
Method#7:numpy():
Algorithm:
1.Convert the given string into a list of characters using the list() method.
2.Create a numpy array from the list of characters using the np.array() method.
3.Use the np.char.isupper() method to check whether each character is uppercase or not.
4.Convert the numpy array to a list using the tolist() method.
5.Use the np.where() method to find the indices where the characters are uppercase.
6.Convert the indices to a list and return the list.
Python3
import numpy as nptest_str = 'GeeKsFoRGEEks'# printing original stringprint("The original string is : " + str(test_str))arr = np.array(list(test_str))res = list(np.where(np.char.isupper(arr.tolist()))[0])print("Uppercase elements indices : " + str(res))#This code is contributed by Jyothi pinjala |
Output:
The original string is : GeeKsFoRGEEks
Uppercase elements indices : [0, 3, 5, 7, 8, 9, 10]
Time complexity: O(n)
The time complexity of the code is O(n) because it involves converting the string to a list, creating a numpy array, and then checking whether each character in the array is uppercase or not. All these operations take O(n) time.
Space complexity: O(n)
The space complexity of the code is O(n) because it involves creating a list of characters from the string, creating a numpy array from the list, and then creating a list from the numpy array. All these operations require O(n) space.
