20. Valid Parentheses | LeetCode | Dart
Welcome back to our coding interview prep series! In today's video, we'll tackle the popular LeetCode problem "Valid Parentheses". This is a classic question often asked in coding interviews to test your understanding of data structures and your problem-solving skills. We'll break down the problem, discuss the approach, and implement the solution in Dart.
🔍 Problem Description:
The "Valid Parentheses" problem asks us to determine if a given string of parentheses (which may include '()', '{}', and '[]') is valid. A string is considered valid if:
Open brackets are closed by the same type of brackets.
Open brackets are closed in the correct order.
🧩 Key Concepts Covered:
Stack Data Structure: We'll use a stack to keep track of the opening brackets and ensure they are closed in the correct order.
String Traversal: We'll iterate through the string to process each character.
Condition Checking: We'll check for matching pairs and ensure the stack is appropriately managed.
💻 Dart Implementation:
We'll write a clean and efficient Dart function to solve the problem. Here's a quick overview of the steps:
Initialize an empty stack using a List in Dart.
Create a Map to map closing brackets to their corresponding opening brackets.
Iterate through the string using a for loop:
If it's an opening bracket, add it to the stack.
If it's a closing bracket, check if it matches the top of the stack using the last property.
After processing the string, check if the stack is empty using the isEmpty property.
📘 Chapters:
00:00 - Problem Statement
01:50 - Explaining Approach
05:50 - Writing Code
13:02 - Running & Submitting
13:35 - Conclusion
🏷️Tags:
#LeetCode #ValidParentheses #Dart #CodingInterview #Programming #TechInterview #DataStructures #Algorithms #Coding