Hi Guys,
I am using the leetcode for more than a year. And solved 500+ questions so far but not in consistent manner. I feel that my algorithmic thinking has improved but speed is not good. My interview is scheduled with Google and I have only one month in my hand. Google expects that the candidate should wrap up all aspects of a problem within 20 minutes. But my speed is suitable for easy level problem only that i can finish within 20 minutes. For a medium level question I take around 35-45 minutes to finish or may be longer sometime. And for any hard problem I take more than a hour to complete. I am worry how to crack Google like interview. My all efforts so far will go in vain if not able to overcome this weakness. Please give some suggestions, which might change my way of prepration and improve me in one month to meet the google expectations.

Idea come quickly how to solve, but wrapping up the idea and writing the code takes long time and exceeds the time limit. Please help by suggesting.