Some tips: On the first problem It's possible to avoid the unnecessary nested loops: You can solve the problem with just one loop, which will give an O(n) algorithm. Also, try to use more meaningful names for variables. Don't forget to handle invalid inputs: It's not a good strategy to consider any input other than C, D, or + as an integer.

You have done a great job here, my brother. One thing I got from your presentation is the principle of separation of concern and understanding the actual questions or requirements is essential. I never thought I could access the last two indexes; I only knew of one in a list. Thanks for the method, and I am grateful.

Wow! happy to discover your channel. I am preparing to take a Javascript live coding challenge, at least you have given me a hint of what to expect.

You have done a great job, Your video is helping me to prepare for a C# challenge, Thank you. int sum = 0; ArrayList arrList = new ArrayList(); for (int i=0; i< ops.Length;i++) { int Num = 0; sum = 0; if (int.TryParse(ops[i],out Num)) { arrList.Add(Num); } else if(ops[i]=="+") { sum =(int) arrList[arrList.Count - 1]; sum += (int)arrList[arrList.Count - 2]; arrList.Add(sum); } else if (ops[i] == "D") { sum = 2*(int)arrList[arrList.Count - 1]; arrList.Add(sum); } else if (ops[i] == "C") { arrList.RemoveAt(arrList.Count - 1); } } sum = 0; for (int i = 0; i < arrList.Count; i++) { sum += (int)arrList[i]; } return sum;

Thank you so much. Great content

Wow!! Thànk you so much for this. Nice content 👌 The background music is perfect for learning.

Im looking forward to develop my skills in programming from your channel.Thanks

I liked the solution very much I've also tried one. public int CalPointsFunc(string[] args) { int output; List record = new List(); foreach(string arg in args) { if (Int32.TryParse(arg, out output)) { record.Add(Int32.Parse(arg)); } else { if (arg == "C") record.RemoveAt(record.Count - 1); else if (arg == "D") record.Add(record.Last() * 2); else if (arg == "+") record.Add(record[record.Count - 2] + record.Last()); } } return record.Sum(); } Thanks

This is great content. Looking forward to try the live coding challenge in Kotlin

Can't wait for the full C# course. Im interested in learning that language

I really appreciate the background music. Helps my attention

Why is the music playing in the background when doing a fully concentrated work?

why didnt u make integer list you couldve only needed to parse once while adding right?

Fantastic work

I recreated your solution using much shorter syntax. Here it is ... class Solution { public int CalPoints(string[] ops) { var opsList = new List(); var count = 0; foreach(var op in ops) { if (op.Equals("+")) { var val = opsList[opsList.Count -1] + opsList[opsList.Count - 2]; opsList.Add(val); } else if (op.Equals("D")) { var val = opsList[opsList.Count - 1] * 2; opsList.Add(val); } else if (op.Equals ("C")) { opsList.RemoveAt(opsList.Count - 1); } else { opsList.Add(int.Parse(op)); } } foreach(var op in opsList) { count += op; } return count; } } class CalPoints { public static void Main(string[] args) { var solution = new Solution(); var space = new Char[] { ' ' }; string[] ops = Console.ReadLine().Split(space); int output = solution.CalPoints(ops); Console.WriteLine(output.ToString()); } }

I did something like that yesterday, un VS works ok but un the turing web give me a sintaxis error in " value.Count - 1 " for get the last member, specificly un the -

Ty for the video! Your explanation is great and is helping me to prepare for a C# challenge. Just a question, why not to put the foreach (var val in opsList) [...] segment outside all if statements instead of copying and repeating it for each of them? I may be missing something.

Great work

Don't stop the good work

I like your presentation

I try to write before watching your solution. Still refactor should be done. Here it is: public int Calculate(string[] scores) { const string CANCEL = "C"; const string DOUBLE = "D"; const string ADD = "+"; if (scores == null || scores.Length == 0) { return 0; } var records = new List(); foreach (var score in scores) { switch (score) { case CANCEL: if(records.Count == 0) throw new Exception($"{CANCEL} operator cannot be used first!"); records.RemoveAt(records.Count - 1); continue; case DOUBLE: if (records.Count == 0) throw new Exception($"{DOUBLE} operator cannot be used first!"); records.Add(records[^1] * 2); continue; case ADD: if (records.Count < 2) throw new Exception($"{ADD} operator cannot be used for first two values!"); records.Add(records[^1] + records[^2]); continue; default: if (!int.TryParse(score, out int number)) { throw new ArgumentException($"Unknown score specifier: {score}"); } records.Add(number); continue; } } return records.Sum(); }

My solution, nice and clean public int CalPoints(string[] ops) { var record = new List(); foreach (var item in ops) { switch (item) { case var _ when int.TryParse(item, out int value): record.Add(value); break; case "+": record.Add(record[^2] + record[^1]); break; case "D" or "d": record.Add(2 * record[^1]); break; case "C" or "c": record.RemoveAt(record.Count - 1); break; } } return record.Sum(); } }

Can you share this script in Java?

Thanks it was great! and here is an other solution: public static int CalPoints(string[] ops) { Stack stack = new Stack(); foreach (string op in ops) { if (int.TryParse(op, out int score)) { stack.Push(score); } else if (op == "+") { int prev1 = stack.Pop(); int prev2 = stack.Peek(); int newScore = prev1 + prev2; stack.Push(prev1); stack.Push(newScore); } else if (op == "D") { int prev = stack.Peek(); stack.Push(prev * 2); } else if (op == "C") { stack.Pop(); } } int finalScore = 0; while (stack.Count > 0) { finalScore += stack.Pop(); } return finalScore; }

Hello... I'm new to turing. I'm an intermediate c# programmer. I would like to know your journey with turing... I'm wondering if this can help me in my career path

A stack version for fun var opList = new[] { "5", "2", "C", "D", "+" }; var stk = new Stack(); foreach(var op in opList) { switch(op) { case "+": var lVal = stk.Pop(); var rVal = stk.Peek(); stk.Push(lVal); stk.Push(lVal + rVal); break; case "C": stk.Pop(); break; case "D": stk.Push(stk.Peek() * 2); break; default: stk.Push(int.Parse(op)); break; } } Console.WriteLine(stk.Sum());

Both can be done using single loop. Solution 1 : List result = new List(); for (int i = 0; i < ops.Length; i++) { if (ops[i] == "+") { result.Add(result[result.Count - 1] + result[result.Count - 2]); } else if (ops[i] == "D") { result.Add(result[result.Count - 1] * 2); } else if (ops[i] == "C") { result.RemoveAt(result.Count - 1); } else { result.Add(int.Parse(ops[i])); } } return result.Sum(); ................................. Solution 2: char[] chars = s.ToCharArray(); Stack openParenthesis = new Stack(); foreach (var c in chars) { if(c == '(' || c == '{' || c == '[') { openParenthesis.Push(c); } else if(c == ')') { if(openParenthesis.Peek() == '(') { openParenthesis.Pop(); } } else if(c == '}') { if (openParenthesis.Peek() == '{') { openParenthesis.Pop(); } } else if (c == ']') { if (openParenthesis.Peek() == '[') { openParenthesis.Pop(); } } } return openParenthesis.Count == 0;

Please is the practice question the same as the real test that one will do? Urgent!!!

Nice... i wished you could do it in php. But i guess thats not your stack.

Hello bro, what about the Turing Tests that is before the Coding Challenge ?, that will be more interesting if you show us some skills on that thank you

public static int ProcOpt(string[] opt) { List recordList = new(); for (int i = 0; i < opt.Length; i++) { if (opt[i] == "c") recordList.Remove(recordList.Last()); else if (opt[i] == "d") recordList.Add(recordList.Last() * 2); else if (opt[i] == "+") recordList.Add(recordList.TakeLast(2).Sum()); else recordList.Add(int.Parse(opt[i])); } return recordList.Sum(); }

My way using stack static string GetSum(List input) { long num = 0;result = 0; if (input.Count

Amazing video

I'd like to give you a little better solution ;) public int calPoints(string[] s) { List points = new List(); for (int i = 0; i < s.Length; i++) { if (s[i].Equals("+")) { points.Add(points[points.Count - 2] + points[points.Count-1]); } else if (s[i].Equals("D")) { points.Add(points[points.Count - 1] * 2); } else if (s[i].Equals("C")) { points.RemoveAt(points.Count - 1); } else { points.Add(int.Parse(s[i])); } } int score = 0; foreach (int point in points) score += point; return score; }

internal void Solution() { Stack stack = new Stack(); for (int i = 0; i < arr.Length; i++) { string cc = arr[i]; if (cc == "C") stack.Pop(); else if (cc == "D") { int peek = stack.Peek(); stack.Push(peek * 2); } else if (cc == "+") { int prevPeek = stack.Pop(); int newNum = prevPeek + stack.Peek(); stack.Push(prevPeek); stack.Push(newNum); } else stack.Push(int.Parse(cc)); } int res = 0; while (stack.Count() > 0) res += stack.Pop(); Console.WriteLine(res); }

please remove the BG music

Please remove the background music it really sucks