When using a stack to reverse a string, what is the time complexity of the entir
Practice Questions
Q1
When using a stack to reverse a string, what is the time complexity of the entire operation?
O(1)
O(n)
O(log n)
O(n^2)
Questions & Step-by-Step Solutions
When using a stack to reverse a string, what is the time complexity of the entire operation?
Step 1: Understand what a stack is. A stack is a data structure that follows Last In First Out (LIFO) principle, meaning the last item added is the first one to be removed.
Step 2: To reverse a string, we need to process each character of the string one by one.
Step 3: For each character in the string, we will push it onto the stack. This means we are adding each character to the stack.
Step 4: After pushing all characters onto the stack, we will start popping them off. Popping means removing the top character from the stack.
Step 5: As we pop each character from the stack, we will build the reversed string.
Step 6: Count the operations: pushing n characters takes O(n) time, and popping n characters also takes O(n) time.
Step 7: Combine the time taken for both operations: O(n) + O(n) = O(n).
Step 8: Conclude that the overall time complexity for reversing a string using a stack is O(n).
