Add Javadoc comments (TheAlgorithms#4745)

src/main/java/com/thealgorithms/dynamicprogramming/RodCutting.java

@@ -1,32 +1,37 @@
 package com.thealgorithms.dynamicprogramming;
 
 /**
- * A DynamicProgramming solution for Rod cutting problem Returns the best
- * obtainable price for a rod of length n and price[] as prices of different
- * pieces
+ * A Dynamic Programming solution for the Rod cutting problem.
+ * Returns the best obtainable price for a rod of length n and price[] as prices of different pieces.
  */
 public class RodCutting {
 
-    private static int cutRod(int[] price, int n) {
+    /**
+     * This method calculates the maximum obtainable value for cutting a rod of length n
+     * into different pieces, given the prices for each possible piece length.
+     *
+     * @param price An array representing the prices of different pieces, where price[i-1]
+     *              represents the price of a piece of length i.
+     * @param n     The length of the rod to be cut.
+     * @return The maximum obtainable value.
+     */
+    public static int cutRod(int[] price, int n) {
+        // Create an array to store the maximum obtainable values for each rod length.
         int[] val = new int[n + 1];
         val[0] = 0;
 
+        // Calculate the maximum value for each rod length from 1 to n.
         for (int i = 1; i <= n; i++) {
-            int max_val = Integer.MIN_VALUE;
-            for (int j = 0; j < i; j++) {
-                max_val = Math.max(max_val, price[j] + val[i - j - 1]);
+            int maxVal = Integer.MIN_VALUE;
+            // Try all possible ways to cut the rod and find the maximum value.
+            for (int j = 1; j <= i; j++) {
+                maxVal = Math.max(maxVal, price[j - 1] + val[i - j]);
             }
-
-            val[i] = max_val;
+            // Store the maximum value for the current rod length.
+            val[i] = maxVal;
         }
 
+        // The final element of 'val' contains the maximum obtainable value for a rod of length 'n'.
         return val[n];
     }
-
-    // main function to test
-    public static void main(String[] args) {
-        int[] arr = new int[] {2, 5, 13, 19, 20};
-        int result = cutRod(arr, arr.length);
-        System.out.println("Maximum Obtainable Value is " + result);
-    }
 }