Add edge case to handle negative rod length in RodCutting algorithm

Author: Chiefpatwal

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

@@ -22,6 +22,9 @@ public static int cutRod(int[] price, int n) {
         if (price == null || price.length == 0) {
             throw new IllegalArgumentException("Price array cannot be null or empty.");
         }
+        if (n < 0) {
+            throw new IllegalArgumentException("Rod length cannot be negative.");
+        }
         // Create an array to store the maximum obtainable values for each rod length.
         int[] val = new int[n + 1];
         val[0] = 0;
@@ -40,4 +43,4 @@ public static int cutRod(int[] price, int n) {
         // The final element of 'val' contains the maximum obtainable value for a rod of length 'n'.
         return val[n];
     }
-}
+}