Added algorithm for Text Justification in Strings (#7354)

* Added algorithm for Text Justification in Strings

* Added algorithm for Text Justification in Strings

strings/text_justification.py

@@ -0,0 +1,92 @@
+def text_justification(word: str, max_width: int) -> list:
+    """
+    Will format the string such that each line has exactly
+    (max_width) characters and is fully (left and right) justified,
+    and return the list of justified text.
+
+    example 1:
+    string = "This is an example of text justification."
+    max_width = 16
+
+    output = ['This    is    an',
+              'example  of text',
+              'justification.  ']
+
+    >>> text_justification("This is an example of text justification.", 16)
+    ['This    is    an', 'example  of text', 'justification.  ']
+
+    example 2:
+    string = "Two roads diverged in a yellow wood"
+    max_width = 16
+    output = ['Two        roads',
+              'diverged   in  a',
+              'yellow wood     ']
+
+    >>> text_justification("Two roads diverged in a yellow wood", 16)
+    ['Two        roads', 'diverged   in  a', 'yellow wood     ']
+
+    Time complexity: O(m*n)
+    Space complexity: O(m*n)
+    """
+
+    # Converting string into list of strings split by a space
+    words = word.split()
+
+    def justify(line: list, width: int, max_width: int) -> str:
+
+        overall_spaces_count = max_width - width
+        words_count = len(line)
+        if len(line) == 1:
+            # if there is only word in line
+            # just insert overall_spaces_count for the remainder of line
+            return line[0] + " " * overall_spaces_count
+        else:
+            spaces_to_insert_between_words = words_count - 1
+            # num_spaces_between_words_list[i] : tells you to insert
+            # num_spaces_between_words_list[i] spaces
+            # after word on line[i]
+            num_spaces_between_words_list = spaces_to_insert_between_words * [
+                overall_spaces_count // spaces_to_insert_between_words
+            ]
+            spaces_count_in_locations = (
+                overall_spaces_count % spaces_to_insert_between_words
+            )
+            # distribute spaces via round robin to the left words
+            for i in range(spaces_count_in_locations):
+                num_spaces_between_words_list[i] += 1
+            aligned_words_list = []
+            for i in range(spaces_to_insert_between_words):
+                # add the word
+                aligned_words_list.append(line[i])
+                # add the spaces to insert
+                aligned_words_list.append(num_spaces_between_words_list[i] * " ")
+            # just add the last word to the sentence
+            aligned_words_list.append(line[-1])
+            # join the aligned words list to form a justified line
+            return "".join(aligned_words_list)
+
+    answer = []
+    line: list[str] = []
+    width = 0
+    for word in words:
+        if width + len(word) + len(line) <= max_width:
+            # keep adding words until we can fill out max_width
+            # width = sum of length of all words (without overall_spaces_count)
+            # len(word) = length of current word
+            # len(line) = number of overall_spaces_count to insert between words
+            line.append(word)
+            width += len(word)
+        else:
+            # justify the line and add it to result
+            answer.append(justify(line, width, max_width))
+            # reset new line and new width
+            line, width = [word], len(word)
+    remaining_spaces = max_width - width - len(line)
+    answer.append(" ".join(line) + (remaining_spaces + 1) * " ")
+    return answer
+
+
+if __name__ == "__main__":
+    from doctest import testmod
+
+    testmod()