Leetcode 404: Sum of Left Leaves
Question
Find the sum of all left leaves in a given binary tree.
[Read More]
-
-
Leetcode 400: Nth Digit
Question Find the nth digit of the infinite integer sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, … [Read More] -
Python Notes: Closures
You can build dynamic functions with a nested function by passing different parameters into it. This technique of using the values of outside parameters within a dynamic function is called closures. For example, [Read More] -
Python Notes: Variable Visibility
Global Variable In Python, a variable declared outside of the function or in global scope is known as global variable. This means, global variable can be accessed (read) inside or outside of the function. [Read More] -
Python Notes: Decorators
Decorator can add additional functionality to existing functions. It takes a function and returns a new function: [Read More] -
Python Notes: HTTP Requests
Simple HTTP Request For really simple HTTP client code, using the built-in urllib module is usually fine. [Read More] -
Leetcode 399: Evaluate Division
Question Equations are given in the format A / B = k, where A and B are variables represented as strings, and k is a real number (floating point number). Given some queries, return the answers. If the answer does not exist, return -1.0. [Read More] -
Leetcode 398: Random Pick Index
Question Given an array of integers with possible duplicates, randomly output the index of a given target number. You can assume that the given target number must exist in the array. [Read More] -
Leetcode 397: Integer Replacement
Question Given a positive integer n and you can do operations as follow: [Read More] -
Leetcode 396: Rotate Function
Question Given an array of integers A and let n to be its length. [Read More] -
Leetcode 395: Longest Substring with At Least K Repeating Characters
Question Find the length of the longest substring T of a given string (consists of lowercase letters only) such that every character in T appears no less than k times. [Read More] -
Leetcode 394: Decode String
Question Given an encoded string, return it’s decoded string. [Read More] -
Java Operator Precedence
postfix _expr_++ _expr_-- unary ++_expr_ --_expr_ +_expr_ -_expr_ ~ ! multiplicative * / % additive + - shift << >> >>> relational < > <= >= instanceof equality == != bitwise AND & bitwise exclusive OR ^ bitwise inclusive OR | logical AND && logical OR || ternary ? :... [Read More] -
Leetcode 393: UTF-8 Validation
Question A character in UTF8 can be from 1 to 4 bytes long, subjected to the following rules: [Read More] -
Leetcode 392: Is Subsequence
Question Given a string s and a string t, check if s is subsequence of t. [Read More]