Problem Solving 101 [0]
We’ll be starting a series to improve our problem solving skills:
We’ll discuss the following problems in this stream:
1. Codeforces 306A #
You are given string s. Your task is to determine if the given string s contains two non-overlapping substrings "AB" and "BA" (the substrings can go in any order).
Input
The only line of input contains a string s of length between 1 and 105 consisting of uppercase Latin letters.
Output
Print "YES" (without the quotes), if string s contains two non-overlapping substrings "AB" and "BA", and "NO" otherwise.
2. Write a function that takes a list of strings an prints them, one per line, in a rectangular frame. For example the list [“Hello”, “World”, “in”, “a”, “frame”] gets printed as: #
*********
* Hello *
* World *
* in *
* a *
* frame *
*********
3. Write a function that merges two sorted lists into a new sorted list. [1,4,6],[2,3,5] → [1,2,3,4,5,6]. You can do this quicker than concatenating them followed by a sort. #
4. Balanced Parentheses (easy) #
Given a string str of length N, consisting of ‘(‘ and ‘)‘ only, the task is to check whether it is balanced or not.
Examples:
Input: str = “((()))()()”
Output: Balanced
Input: str = “())((())”
Output: Not Balanced