import java.util.*; class Solution { public List<Integer> findMinHeightTrees(int n, int[][] edges) { if (n == 1) { return Collections.singletonList(0); } List<Integer> result = new ArrayList<>(); Map<Integer, List<Integer>> map = new HashMap<>(); // Build the adjacency list for (int[] edge : edges) { int u = edge[0]; int v = edge[1]; map.computeIfAbsent(u, k -> new ArrayList<>()).add(v); map.computeIfAbsent(v, k -> new ArrayList<>()).add(u); } Queue<Integer> leaves = new LinkedList<>(); // Add initial leaf nodes to the queue for (int node : map.keySet()) { if (map.get(node).size() == 1) { leaves.offer(node); } } while (n > 2) { int size = leaves.size(); n -= size; for (int i = 0; i < size; i++) { int leaf = leaves.poll(); int neighbor = map.get(leaf).iterator().next(); // Get the only neighbor map.get(neighbor).remove(Integer.valueOf(leaf)); // Remove leaf from neighbor's adjacency list if (map.get(neighbor).size() == 1) { leaves.offer(neighbor); } } } result.addAll(leaves); return result; } }

give the code

errors from EmployeeMapper = java: cannot find symbol symbol: method getLastName() location: variable employeeDto of type com.developer.coder.ems.dto.EmployeeDto also the same for employee too

Q2

Bro, thumbnail??☠

thank you

Lage raho bro ❤

DP: class Solution { public long minimumTotalDistance(List<Integer> robot, int[][] factory) { Collections.sort(robot); Arrays.sort(factory, Comparator.comparingInt(a -> a[0])); List<Integer> factoryPositions = new ArrayList<>(); for (int[] f : factory) { for (int i = 0; i < f[1]; i++) { factoryPositions.add(f[0]); } } int robotCount = robot.size(); int factoryCount = factoryPositions.size(); long[] next = new long[factoryCount+1]; long[] current = new long[factoryCount+1]; for( int i=robotCount -1;i>=0;i--){ //no factories left case if(i!= robotCount -1 ) next[factoryCount] = (long) 1e12; current[factoryCount] = (long) 1e12; for(int j = factoryCount -1 ;j>=0;j--){ //assign current robot to current factory long assign = Math.abs((long) robot.get(i) - factoryPositions.get(j)) + next[j+1]; //skip current factory for this robot long skip = current[j+1]; //take the min option current[j] = Math.min(assign,skip); } System.arraycopy(current,0,next,0,factoryCount+1); } return current[0]; } }

Recursion+Memo class Solution { public long minimumTotalDistance(List<Integer> robot, int[][] factory) { Collections.sort(robot); Arrays.sort(factory, Comparator.comparingInt(a -> a[0])); List<Integer> factoryPositions = new ArrayList<>(); for(int[] f : factory ){ for(int i=0;i<f[1];i++){ factoryPositions.add(f[0]); } } int robotCount = robot.size(); int factoryCount = factoryPositions.size(); long[][] memo = new long[robotCount][factoryCount]; for(long[] row: memo){ Arrays.fill(row, -1); } return calculateMinDistance(0,0, robot, factoryPositions, memo); } private long calculateMinDistance(int robotIdx, int factoryIdx, List<Integer> robot, List<Integer> factoryPositions, long[][] memo ){ //All robots assigned if(robotIdx == robot.size()) return 0; //No factories left to assign if(factoryIdx == factoryPositions.size()) return (long) 1e12; //check memo if(memo[robotIdx][factoryIdx] != -1){ return memo[robotIdx][factoryIdx]; } //option:1 assign current robot to current factory long assign = Math.abs(robot.get(robotIdx) - factoryPositions.get(factoryIdx)) + calculateMinDistance(robotIdx+1,factoryIdx+1, robot, factoryPositions, memo); //option:2 Skip current factory for the current robot long skip = calculateMinDistance(robotIdx,factoryIdx + 1, robot, factoryPositions, memo); memo[robotIdx][factoryIdx] = Math.min(assign,skip); return memo[robotIdx][factoryIdx]; } }

can you provide the code for both approaches

you should provide some soft copy of the code

Thanks for hint here is my solution which got accepted! Java class Solution { public int lengthAfterTransformations(String s, int t) { int mod=1000000007; int[] hash=new int[26]; int ans=0; for(int i=0;i<s.length();i++){ char c=s.charAt(i); hash[c-'a']++; } for(int i=0;i<t;i++){ int a=hash[25],b=hash[25]; hash[25]=0; for(int j=25;j>0;j--){ hash[j]=hash[j-1]; hash[j-1]=0; } hash[0]=a; hash[1]=(hash[1]+b)%mod; } for(int ele:hash){ ans=(ans%mod+ele)%mod; } return ans; } }

Nice explanation.. Keep it up bro👍

sir pls explain how the code will work on it by step by step explain with example

Please try 🎧 incase voice is not clear and audible. Getting some issues with the old recorder.😊

2 pointers: (Sliding Window) (Time Complexity) Let n be the total number of elements across all lists and k be the number of lists. Time complexity: O(nlogn) The first nested loop iterates over k lists, and for each list, it iterates through its elements. In the worst case, this requires O(n) time since we are processing all elements once. After merging, we sort the merged array which contains n elements. Sorting has a time complexity of O(nlogn). The two-pointer approach iterates through the merged list once (with the right pointer) and may also move the left pointer forward multiple times. In total, each pointer will traverse the merged list at most n times. Combining these steps, the overall time complexity is: O(nlogn)

Priority Queue: (Time Complexity) Let n be the total number of elements across all lists and k be the number of lists. Time complexity: O(nlogk) The initial loop that inserts the first element from each list into the priority queue runs in O(k). The while loop continues until we have exhausted one of the lists in the priority queue. Each iteration of the loop involves: Extracting the minimum element from the priority queue, which takes O(logk). Inserting a new element from the same list into the priority queue, which also takes O(logk). In the worst case, we will process all n elements, leading to a total complexity of O(nlogk).

Brute Force: (Time Complexity ) Let n be the total number of elements across all lists and k be the number of lists. Time complexity: O(n⋅k) In each iteration of the while (true) loop, we traverse all k lists to find the current minimum and maximum. This takes O(k) time. The loop continues until at least one of the lists is fully traversed. In the worst case, every element from every list is visited, and the total number of elements across all lists is n. Therefore, the loop runs O(n) times. Overall, the time complexity becomes O(n⋅k).

Using Arrays: class CustomStack { private int[] stack; // Array to store the stack elements private int top; // Pointer to the top of the stack private int maxSize; // Maximum size of the stack // Constructor to initialize the stack and set the maximum size public CustomStack(int maxSize) { this.stack = new int[maxSize]; // Fixed-size array for the stack this.top = -1; // Initialize top as -1 (empty stack) this.maxSize = maxSize; } // Pushes an element onto the stack if there's space public void push(int x) { if (top < maxSize - 1) { // Check if there's space in the stack top++; // Move top pointer to the next empty spot stack[top] = x; // Add element to the stack } } // Pops and returns the top element of the stack, or -1 if it's empty public int pop() { if (top == -1) { // If the stack is empty, return -1 return -1; } else { return stack[top--]; // Return top element and decrement the top pointer } } // Increments the bottom k elements by val public void increment(int k, int val) { int limit = Math.min(k, top + 1); // Find how many elements we can increment for (int i = 0; i < limit; i++) { stack[i] += val; // Increment each of the bottom k elements } } } /** * Your CustomStack object will be instantiated and called as such: * CustomStack obj = new CustomStack(maxSize); * obj.push(x); * int param_2 = obj.pop(); * obj.increment(k,val); */

Some more ways to solve this problem: Using ArrayList : class CustomStack { private ArrayList<Integer> stack; private int maxSize; public CustomStack(int maxSize) { this.stack = new ArrayList<>(); this.maxSize = maxSize; } // Pushes an element to the top of the stack if it hasn't reached the max size public void push(int x) { if (stack.size() < maxSize) { stack.add(x); } } // Pops and returns the top element of the stack or -1 if the stack is empty public int pop() { if (stack.isEmpty()) { return -1; } else { return stack.remove(stack.size() - 1); // Removes the top element } } // Increments the bottom k elements by val public void increment(int k, int val) { int limit = Math.min(k, stack.size()); // Ensures we don't exceed the stack size for (int i = 0; i < limit; i++) { stack.set(i, stack.get(i) + val); // Increment each of the bottom k elements } } }

sir can you give the code for string approach for the above problem

thanks for the explanation sir

clear English, written out dry run, best explanation on youtube for this question! including time/space at the end would make this video a bit better. thank you!

Hello brother, your tutorials are really helpful. I would like to contact you, if possible share your contact info..

Nice

Nice one

Bro please, first explain the problem then explain the solution , because it'll give us the time to try it by ourselves.. cause most newbies like me can't understand the problem like this ..

NICE SUPER EXCELLENT MOTIVATED

Thanks for daily problem videos

Hey please share this project GitHub link

Note: Please use earphones 🎧 for better audio quality. I hope everyone is able to send the data and get the list of employees using frontend part. If you have any queries, please let me know in the comments!!!! Consistency is the 🗝️ key to success!!!

nice one

Approach 2 (Without using Map): import java.util.*; class Solution { public double maxProbability(int n, int[][] edges, double[] succProb, int start_node, int end_node) { List<double[]>[] graph = new List[n]; for (int i = 0; i < n; i++) { graph[i] = new ArrayList<>(); } for (int i = 0; i < edges.length; i++) { int u = edges[i][0]; int v = edges[i][1]; double p = succProb[i]; graph[u].add(new double[]{v, p}); graph[v].add(new double[]{u, p}); } PriorityQueue<double[]> pq = new PriorityQueue<>((a, b) -> Double.compare(b[1], a[1])); pq.add(new double[]{start_node, 1.0}); double[] r = new double[n]; r[start_node] = 1.0; while (!pq.isEmpty()) { double[] curr = pq.poll(); int u = (int) curr[0]; double p = curr[1]; if (u == end_node) { return p; } for (double[] neighbor : graph[u]) { int v = (int) neighbor[0]; double prob = p * neighbor[1]; if (prob > r[v]) { r[v] = prob; pq.add(new double[]{v, prob}); } } } return 0.0; } }

Thank you so much! I was struggling to understand Spring Boot even after reading the documentation and searching everywhere, but this video explained it perfectly. As someone new to Spring Boot, this really helped me a lot!

Hi Everyone, I hope you’ve all completed the backend and frontend tasks to retrieve the list of employees. If you’re encountering any issues, please let me know in the comments. Note: For better audio quality, please use earphones. There was an issue with the recorder that I discovered only after the recording was finished.

Your audio is very hard to hear

NICE SUPER EXCELLENT MOTIVATED

Use some light IDEs and create some moderate type projects using React and Spring Boot

Part 1 : kzbin.info/www/bejne/j6nVe2B-bLprd8k

✅

Nicely explained..

I didn't have much time today, so I put this video together quickly to help you maintain your daily streak. If you have any questions or need further clarification, please let me know, and I'll do my best to provide a detailed explanation. Thank you for your understanding and support.😊

I did not understand the input. We are provided with a 2D integer array and the input is string. And we haven't mentioned strings anywhere in the program and we are not checking with the string value then how are we able to determine if adjacent or diagonal value is asked. Can anyone explain?

Please

Bro 2nd question ka solution

How can they term it as "EASY"?

Very simple and nice explanation , Thankyou, keep it up .

Correction: Instead of saying 1, 2, 4, 8 are divisible by 16, I mistakenly referred to 1, 2, 4, and 8 as special numbers. Ignore that part (from 03:24 to 03:42). Special numbers are only those that are divisible by 1 and are squares of prime numbers(2,3,5,7,11 etc), like 4, 9, 25, 49, and 121 are special numbers according to this problem.

How 8 is a special number?

Great explanation