Given the root of a binary tree, return the same tree where every subtree (of the given tree) not containing a 1 has been removed.
A subtree of a node node is node plus every node that is a descendant of node.
861. Score After Flipping Matrix
You are given an m x n binary matrix grid.
A move consists of choosing any row or column and toggling each value in that row or column (i.e., changing all 0’s to 1’s, and all 1’s to 0’s).
Every row of the matrix is interpreted as a binary number, and the score of the matrix is the sum of these numbers.
Return the highest possible score after making any number of moves (including zero moves).
1347. Minimum Number of Steps to Make Two Strings Anagram
You are given two strings of the same length s and t. In one step you can choose any character of t and replace it with another character.
Return the minimum number of steps to make t an anagram of s.
An Anagram of a string is a string that contains the same characters with a different (or the same) ordering.