Given a string s consisting of words and spaces, return the length of the last word in the string.
s
A word is a maximal substring consisting of non-space characters only.
Given two strings needle and haystack, return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.
needle
haystack
-1
You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0's.
digits
digits[i]
ith
0
Given a binary tree, determine if it is height-balanced.
A phrase is a palindrome if, after converting all uppercase letters into lowercase letters and removing all non-alphanumeric characters, it reads the same forward and backward. Alphanumeric characters include letters and numbers.
Given the root of a binary tree, check whether it is a mirror of itself (i.e., symmetric…
root