haoweizh

摘要： Problem: There is a garden with N slots. In each slot, there is a flower. The N flowers will bloom one by one in N days. In each day, there will be ex 阅读全文

摘要： Problem: Design a search autocomplete system for a search engine. Users may input a sentence (at least one word and end with a special character '#'). 阅读全文

摘要： Problem: A frog is crossing a river. The river is divided into x units and at each unit there may or may not exist a stone. The frog can jump on a sto 阅读全文

摘要： Problem: Given a string S, count the number of distinct, non-empty subsequences of S . Since the result may be large, return the answer modulo 10^9 + 阅读全文