My learning in java

 Nice question 👍 You’re asking: 👉 After finishing subarray problems, what’s the next topic left in arrays in DSA? Let me give you a roadmap of array topics in DSA so you see what comes after subarrays: 🔹 Array Topics in DSA (Progression) Basics Traversal, Insertion, Deletion Searching (Linear, Binary Search) Prefix / Suffix Concepts Prefix Sum Suffix Sum Difference Array Subarrays (you’ve done this) Kadane’s Algorithm (max sum subarray) Sliding Window (fixed & variable size) Two Pointer Technique Problems like Longest Increasing Subarray, Equal 0s & 1s, etc. ✅ You’re here. Subsequences vs Subarrays Subarray = contiguous Subsequence = not necessarily contiguous Example problems: Longest Increasing Subsequence (LIS) Maximum Sum Increasing Subsequence Sorting-based Array Problems Merge Intervals Inversion Count (using merge sort) Sorting 0s,1s,2s (Dutch National Flag) Searching in Arrays ...

//for finding maximum subarray sum:  class Main {     public static void main(String[] args) {         int[] arr = {4, -1, 2, 1};         int cur_sum = arr[0];         int max_sum = arr[0];  // track the best sum so far         for (int i = 1; i < arr.length; i++) {             // either extend the previous subarray OR start fresh from arr[i]             cur_sum = Math.max(arr[i], cur_sum + arr[i]);             // update the maximum sum found so far             max_sum = Math.max(max_sum, cur_sum);         }         System.out.println("Maximum Subarray Sum = " + max_sum);     } } //for finding minimum subarray of the sum:  class Main {     public static void main(String[] args) {       ...

 // Online Java Compiler // Use this editor to write, compile and run your Java code online class Main {     public static void main(String[] args) {        int [] arr = {16, 17, 4, 3, 5, 2};        int [] leader=new int[arr.length];        int index=0;         for(int i=arr.length-1;i>0;i--){     for(int j=i-1;j>=0;j--)     if(arr[i]>arr[j]){         leader[index++]=arr[i];     } } leader[0]=arr[arr.length-1]; for(int ele:leader){     System.out.println(ele); }     } }

//For finding buying and seeling the stock:  class Main {     public static void main(String[] args) {         int[] price = {8, 2, 1, 5, 4, 6};         int min = Integer.MAX_VALUE;         int max = 0;         for(int i=0;i<price.length;i++){             if(price[i]<min){                 min=price[i];             }             else if(price[i]-min>max){                 max=price[i]-min;             }         }         System.out.println("Buy:"+min);                 System.out.println("sell:"+max);     } } //finiding leader in an array: // Online Java Compiler // Use this editor to write, compile and...

class Main {     public static void main(String[] args) {        int [] arr={1,2,-1,-2};        int [] temp_neg=new int [arr.length];        int [] temp_pos=new int [arr.length];        int posindex=0;        int negindex=0;        //storing positive and negative array values        for(int i=0;i<arr.length;i++){            if(arr[i]<0){                temp_neg[negindex++]=arr[i];            }            else{                temp_pos[posindex++]=arr[i];            }        }        int [] combine=new int[temp_neg.length+temp_pos.length];        int i=0,j=0,k=0;     ...

 class Main {     public static void main(String[] args) {        int [] arr={1,2,3,4,4,5,5,5};       // because one element is already present        int [] freq=new int [arr.length];        boolean [] visit=new boolean[arr.length];        int index=0;        //finding elemets with their frequency:        for(int i=0;i<arr.length;i++){               if(visit[i]){                   continue;               }                int count=1;            for(int j=i+1;j<arr.length;j++){                if(arr[i]==arr[j]){                    visit[j]=true;     ...

 // Online Java Compiler // Use this editor to write, compile and run your Java code online    class Main {     public static void main(String[] args) {        int [] arr={1,2,3,4,4,5,5,5};       // because one element is already present        int [] freq=new int [arr.length];        boolean [] visit=new boolean[arr.length];        int index=0;        //finding elemets with their frequency:        for(int i=0;i<arr.length;i++){               if(visit[i]){                   continue;               }                int count=1;            for(int j=i+1;j<arr.length;j++){                if(arr[i]==arr[j])...