update a solution for 970

fishercoder1534 · fishercoder1534 · commit 4be926f4d4ec · 2021-04-30T07:20:23.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_970.java b/src/main/java/com/fishercoder/solutions/_970.java
@@ -8,30 +8,26 @@
 
 public class _970 {
     public static class Solution1 {
-        /**
-         * This approach results in Time Limit Exceeded since it's apparently doing
-         * redundant checks.
-         */
         public List<Integer> powerfulIntegers(int x, int y, int bound) {
-            Set<Integer> result = new HashSet<>();
-            int small = x;
-            int big = y;
-            if (x > y) {
-                small = y;
-                big = x;
-            }
-            int maxPower = bound / small;
-            for (int i = 0; i <= maxPower + 1; i++) {
-                for (int j = 0; j <= maxPower + 1; j++) {
-                    int sum = (int) (Math.pow(small, i) + Math.pow(big, j));
-                    if (sum <= bound) {
-                        result.add(sum);
+            int powerInteger;
+            Set<Integer> set = new HashSet<>();
+            for (int i = 0; i <= bound; i++) {
+                for (int j = 0; j <= bound; j++) {
+                    powerInteger = (int) (Math.pow(x, i) + Math.pow(y, j));
+                    if (powerInteger <= bound) {
+                        set.add(powerInteger);
+                    } else {
+                        break;
+                    }
+                    if (y == 1) {
+                        break;
                     }
                 }
+                if (x == 1) {
+                    break;
+                }
             }
-            List<Integer> list = new ArrayList<>(result);
-            Collections.sort(list);
-            return list;
+            return new ArrayList<>(set);
         }
     }
 
diff --git a/src/test/java/com/fishercoder/_970Test.java b/src/test/java/com/fishercoder/_970Test.java
@@ -1,55 +1,60 @@
 package com.fishercoder;
 
+import com.fishercoder.common.utils.CommonUtils;
 import com.fishercoder.solutions._970;
+
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+
 import org.junit.BeforeClass;
 import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
 
 public class _970Test {
-  private static _970.Solution1 solution1;
-  private static _970.Solution2 solution2;
-
-  @BeforeClass
-  public static void setup() {
-    solution1 = new _970.Solution1();
-    solution2 = new _970.Solution2();
-  }
-
-  @Test
-  public void test1() {
-    assertEquals(Arrays.asList(2, 3, 4, 5, 7, 9, 10), solution1.powerfulIntegers(2, 3, 10));
-    assertEquals(Arrays.asList(2, 3, 4, 5, 7, 9, 10), solution2.powerfulIntegers(2, 3, 10));
-  }
-
-  @Test
-  public void test2() {
-    assertEquals(Arrays.asList(2, 4, 6, 8, 10, 14), solution1.powerfulIntegers(3, 5, 15));
-    assertEquals(Arrays.asList(2, 4, 6, 8, 10, 14), solution2.powerfulIntegers(3, 5, 15));
-  }
-
-  @Test
-  public void test3() {
-    assertEquals(Arrays.asList(2, 3, 5, 7, 8, 9, 10), solution1.powerfulIntegers(2, 6, 12));
-    assertEquals(Arrays.asList(2, 3, 5, 7, 8, 9, 10), solution2.powerfulIntegers(2, 6, 12));
-  }
-
-  @Test
-  public void test4() {
-    assertEquals(Arrays.asList(2, 3, 5, 9, 10, 11), solution1.powerfulIntegers(2, 9, 12));
-    assertEquals(Arrays.asList(2, 3, 5, 9, 10, 11), solution2.powerfulIntegers(2, 9, 12));
-  }
-
-  @Test
-  public void test5() {
-    assertEquals(Arrays.asList(2, 91, 180, 8101, 8190, 16200, 729001, 729090,
-        737100), solution1.powerfulIntegers(90, 90, 1000000));
-    List<Integer> actual = solution2.powerfulIntegers(90, 90, 1000000);
-    Collections.sort(actual);
-    assertEquals(Arrays.asList(2, 91, 180, 8101, 8190, 16200, 729001, 729090,
-        737100), actual);
-  }
+    private static _970.Solution1 solution1;
+    private static _970.Solution2 solution2;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _970.Solution1();
+        solution2 = new _970.Solution2();
+    }
+
+    @Test
+    public void test1() {
+        assertEquals(Arrays.asList(2, 3, 4, 5, 7, 9, 10), solution1.powerfulIntegers(2, 3, 10));
+        assertEquals(Arrays.asList(2, 3, 4, 5, 7, 9, 10), solution2.powerfulIntegers(2, 3, 10));
+    }
+
+    @Test
+    public void test2() {
+        assertEquals(Arrays.asList(2, 4, 6, 8, 10, 14), solution1.powerfulIntegers(3, 5, 15));
+        assertEquals(Arrays.asList(2, 4, 6, 8, 10, 14), solution2.powerfulIntegers(3, 5, 15));
+    }
+
+    @Test
+    public void test3() {
+        assertEquals(Arrays.asList(2, 3, 5, 7, 8, 9, 10), solution1.powerfulIntegers(2, 6, 12));
+        assertEquals(Arrays.asList(2, 3, 5, 7, 8, 9, 10), solution2.powerfulIntegers(2, 6, 12));
+    }
+
+    @Test
+    public void test4() {
+        assertEquals(Arrays.asList(2, 3, 5, 9, 10, 11), solution1.powerfulIntegers(2, 9, 12));
+        assertEquals(Arrays.asList(2, 3, 5, 9, 10, 11), solution2.powerfulIntegers(2, 9, 12));
+    }
+
+    @Test
+    public void test5() {
+        CommonUtils.printList(solution1.powerfulIntegers(90, 90, 1000000));
+        CommonUtils.printList(solution2.powerfulIntegers(90, 90, 1000000));
+    }
+
+    @Test
+    public void test6() {
+        assertEquals(Arrays.asList(2), solution1.powerfulIntegers(1, 1, 40000));
+        assertEquals(Arrays.asList(2), solution2.powerfulIntegers(1, 1, 40000));
+    }
 }
