fixing bugs - no longer panics when iteration < 0 or MaxIteration >= len(TheFibonacciSequence)-1

cli/main.go

@@ -71,6 +71,14 @@ func main() {
 			fmt.Fprintf(os.Stderr, "iteration %d would overflow int64 - using %d\n", iteration, maxIteration)
 			iteration = maxIteration
 		}
+	} else if iteration < 0 {
+		switch doPanic {
+		case true:
+			panic(fmt.Sprintf("error: input %d would cause index out of range exception\n", iteration))
+		default:
+			fmt.Fprintf(os.Stderr, "error: input %d would cause index out of range exception - using 0\n", iteration)
+			iteration = 0
+		}
 	}
 
 	backoff := &fibonacci.FibonacciBackoff{