43. Multiply StringsThis question is very similar with question 2. Add Two Numbers.It's all math problems,if you want to understand this question clearly.You should draw a picture first.We can fin...
29. Divide Two IntegersThis question is a very interesting question.It does a lot of conditional restrictions.So we can only go back to the simplest mathematical method to think.What is division.7/...
15. 3SumThis question is similar with 1. Two Sum.But they have some different,the main different is this question is the solution set must not contain duplicate triplets.So we can't just use enumer...
2. Add Two NumbersThis question is mathematics question. Each of us must have learned addition.So this is a carry sums of addition question.The question becomes clear.Addition of the same rank from...
374. Guess Number Higher or LowerThis question is also a Binary Search question.We can notice one thing.1 <= pick <= n.So this question is search 1 between n.We can search their mid number.If...
