Pasting

Challenge Difficulty: Medium | Estimated completion time: ~25 minutes

Given a sentence containing few instances of "Ctrl + C" and "Ctrl + V", return the sentence after those keyboard shortcuts have been applied!

• "Ctrl + C" will copy all text behind it.
• "Ctrl + V" will do nothing if there is no "Ctrl + C" before it.
• A "Ctrl + C" which follows another "Ctrl + C" will overwrite what it copies.

Examples

#Example 1
keyboardShortcut("the egg and Ctrl + C Ctrl + V the spoon")
output = "the egg and the egg and the spoon"
 
#Example 2
keyboardShortcut("WARNING Ctrl + V Ctrl + C Ctrl + V")
output = "WARNING WARNING"
 
#Example 3
keyboardShortcut("The Ctrl + C Ctrl + V Town Ctrl + C Ctrl + V")
output = "The The Town The The Town"

Notes

• Keyboard shortcut commands will appear like normal words in a sentence but shouldn’t be copied themselves (see example #2).
• Pasting should add a space between words.

Solution

Python

def keyboardShortcut(sentence: str) -> str: """ Process a sentence containing Ctrl+C and Ctrl+V keyboard shortcuts. Ctrl+C copies all text before it. Ctrl+V pastes the copied text. A Ctrl+C following another Ctrl+C overwrites the clipboard. Args: sentence: String containing text and keyboard shortcut commands. Returns: The sentence after applying all keyboard shortcuts. Examples: >>> keyboardShortcut("the egg and Ctrl + C Ctrl + V the spoon") 'the egg and the egg and the spoon' >>> keyboardShortcut("WARNING Ctrl + V Ctrl + C Ctrl + V") 'WARNING WARNING' """ words = sentence.split() result = [] clipboard = "" word_index = 0 while word_index < len(words): if word_index + 2 < len(words) and words[word_index] <span class="text-highlight"> "Ctrl" and words[word_index + 1] </span> "+" and words[word_index + 2] == "C": # Ctrl + C: copy all previous text clipboard = " ".join(result) word_index += 3 elif word_index + 2 < len(words) and words[word_index] <span class="text-highlight"> "Ctrl" and words[word_index + 1] </span> "+" and words[word_index + 2] == "V": # Ctrl + V: paste clipboard content if clipboard: result.append(clipboard) word_index += 3 else: result.append(words[word_index]) word_index += 1 return " ".join(result) if __name__ <span class="text-highlight"> "__main__": # Test cases assert keyboardShortcut("the egg and Ctrl + C Ctrl + V the spoon") </span> "the egg and the egg and the spoon" assert keyboardShortcut("WARNING Ctrl + V Ctrl + C Ctrl + V") <span class="text-highlight"> "WARNING WARNING" assert keyboardShortcut("The Ctrl + C Ctrl + V Town Ctrl + C Ctrl + V") </span> "The The Town The The Town" print("All test cases passed!")

Output