Python: Find smallest window that contains all characters of a given string
Python String: Exercise-75 with Solution
Write a Python program to find smallest window that contains all characters of a given string.
Sample Solution:
Python Code:
from collections import defaultdict
def find_sub_string(str):
str_len = len(str)
# Count all distinct characters.
dist_count_char = len(set([x for x in str]))
ctr, start_pos, start_pos_index, min_len = 0, 0, -1, 9999999999
curr_count = defaultdict(lambda: 0)
for i in range(str_len):
curr_count[str[i]] += 1
if curr_count[str[i]] == 1:
ctr += 1
if ctr == dist_count_char:
while curr_count[str[start_pos]] > 1:
if curr_count[str[start_pos]] > 1:
curr_count[str[start_pos]] -= 1
start_pos += 1
len_window = i - start_pos + 1
if min_len > len_window:
min_len = len_window
start_pos_index = start_pos
return str[start_pos_index: start_pos_index + min_len]
str1 = "asdaewsqgtwwsa"
print("Original Strings:\n",str1)
print("\nSmallest window that contains all characters of the said string:")
print(find_sub_string(str1))
Sample Output:
Original Strings: asdaewsqgtwwsa Smallest window that contains all characters of the said string: daewsqgt
Pictorial Presentation:
Flowchart:

Visualize Python code execution:
The following tool visualize what the computer is doing step-by-step as it executes the said program:
Python Code Editor:
Have another way to solve this solution? Contribute your code (and comments) through Disqus.
Previous: Write a Python program to find the minimum window in a given string which will contain all the characters of another given string.
Next: Write a Python program to count number of substrings from a given string of lowercase alphabets with exactly k distinct (given) characters.
What is the difficulty level of this exercise?
Test your Programming skills with w3resource's quiz.
Python: Tips of the Day
What is the difference between Python's list methods append and extend?
append: Appends object at the end.
x = [1, 2, 3] x.append([4, 5]) print (x)
Output:
[1, 2, 3, [4, 5]]
extend: Extends list by appending elements from the iterable.
x = [1, 2, 3] x.extend([4, 5]) print (x)
Output:
[1, 2, 3, 4, 5]
Ref: https://bit.ly/2AZ6ZFq
- New Content published on w3resource:
- HTML-CSS Practical: Exercises, Practice, Solution
- Java Regular Expression: Exercises, Practice, Solution
- Scala Programming Exercises, Practice, Solution
- Python Itertools exercises
- Python Numpy exercises
- Python GeoPy Package exercises
- Python Pandas exercises
- Python nltk exercises
- Python BeautifulSoup exercises
- Form Template
- Composer - PHP Package Manager
- PHPUnit - PHP Testing
- Laravel - PHP Framework
- Angular - JavaScript Framework
- Vue - JavaScript Framework
- Jest - JavaScript Testing Framework