Update sort.java

Author: navjotdadwal

Basic Codes/sort.java

@@ -8,40 +8,42 @@ class Main
 {
     void merge(int a[], int l, int m, int r)     // merging the splited sorted arrays
     {
-        int n1 = m - l + 1, n2 = r - m;
+        //merging two arrays i.e L and R
+        int n1 = m - l + 1; // size of the first array
+        int n2 = r - m;  // size of the second array
 
-        int L[] = new int[n1];
-        int R[] = new int[n2];
+        int L[] = new int[n1]; // first array
+        int R[] = new int[n2]; // second array
 
         for (int i = 0; i < n1; ++i)
-            L[i] = a[l + i];
+            L[i] = a[l + i];         // assigning values to the first array
         for (int j = 0; j < n2; ++j)
-            R[j] = a[m + 1 + j];
+            R[j] = a[m + 1 + j];    // assigning values to the second array
 
-        int i = 0, j = 0;
-        int k = l;
-        while (i < n1 && j < n2) {
+        int i = 0, j = 0;  // pointers t array L and R respectively
+        int k = l;  // pointer to the main array
+        while (i < n1 && j < n2) {  // merging until i and j not reach end of the array
             if (L[i] <= R[j]) {
-                a[k++] = L[i++];
+                a[k++] = L[i++];    
             }
             else {
                 a[k++] = R[j++];
             }
         }
-        while (i < n1) {
+        while (i < n1) {  // merging 1st array when 2nd array is completely merged 
             a[k++] = L[i++];
         }
-        while (j < n2) {
+        while (j < n2) {  // merging 2nd array when 1st array is completely merged
             a[k++] = R[j++];
         }
     }
     void sort(int arr[], int l, int r)         // dividing the array then merging sorted arrays
     {
         if (l < r) {
-            int m =l+ (r-l)/2;
-            sort(arr, l, m);
-            sort(arr, m + 1, r);
-            merge(arr, l, m, r);
+            int m =l+ (r-l)/2;  // calculating the mid of the array
+            sort(arr, l, m);   // sorting the left part
+            sort(arr, m + 1, r);  // sorting the right part
+            merge(arr, l, m, r);  // merging the left and right part
         }
     }
     public static void main(String args[])
@@ -51,15 +53,15 @@ public static void main(String args[])
         System.out.print("Enter ten numbers for the array"); 
         for(int i=0; i<10; i++)  
         {  
-          arr[i]=sc.nextInt();  
+          arr[i]=sc.nextInt();   // taking input
         } 
         Main ob = new Main();
-        ob.sort(arr, 0, arr.length - 1);
+        ob.sort(arr, 0, arr.length - 1);  // sorting
 
         System.out.println("\nSorted array");
         int n = arr.length;
         for (int i = 0; i < n; ++i)
-            System.out.print(arr[i] + " ");
+            System.out.print(arr[i] + " ");    // printing the sorted array
         System.out.println();
     }
 }