HW1_done

src/main/java/school/lemon/changerequest/java/introduction/hw1/Task7.java

@@ -28,9 +28,8 @@ public static String getDayTitle(int dayIndex) {
                 return "Sunday";
 
             default:
-                return  "Error";
+                return  "error";
         }
 
-
     }
 }

src/main/java/school/lemon/changerequest/java/introduction/hw1/Task8.java

@@ -3,9 +3,9 @@
 public class Task8 {
     public static int calculateSum(int N) {
         int result = 0;
-        int i;
-        for (i = N; 2 * N >= i; i++)
-            result = (int) (i + Math.pow((2 * N), 2));
+
+        for (int i = N; 2 * N >= i; i++)
+            result+= i*i;
         return result;
     }
 }

src/main/java/school/lemon/changerequest/java/introduction/hw1/Task9.java

@@ -4,14 +4,14 @@ public class Task9 {
 
     public static boolean isPowerOfThree(int n) {
 
-        if (n < 1){
+        if (n <= 1){
             return false;
         }
 
-        while (n % 3 == 0) {
+        while (n>1 && (n % 3) == 0) {
             n = n / 3;
         }
-            return true;
+            return n == 1;
      }
 }