refactor 153

fishercoder1534 · fishercoder1534 · commit c5d360ccfc4f · 2021-10-23T14:07:57.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_153.java b/src/main/java/com/fishercoder/solutions/_153.java
@@ -1,46 +1,28 @@
 package com.fishercoder.solutions;
 
-/**
- * 153. Find Minimum in Rotated Sorted Array
-
-  Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.
-
- (i.e.,  [0,1,2,4,5,6,7] might become  [4,5,6,7,0,1,2]).
-
- Find the minimum element.
-
- You may assume no duplicate exists in the array.
-
- Example 1:
- Input: [3,4,5,1,2]
- Output: 1
-
- Example 2:
- Input: [4,5,6,7,0,1,2]
- Output: 0
-
- */
 public class _153 {
-  public static class Solution1 {
-    public int findMin(int[] nums) {
-      int left = 0;
-      int right = nums.length - 1;
-      if (nums[left] < nums[right]) {
-        return nums[left];
-      }
-      int min = nums[0];
-      while (left + 1 < right) {
-        int mid = left + (right - left) / 2;
-        min = Math.min(min, nums[mid]);
-        if (nums[mid] > nums[left]) {
-          min = Math.min(nums[left], min);
-          left = mid + 1;
-        } else if (nums[mid] < nums[left]) {
-          right = mid - 1;
+    public static class Solution1 {
+        /**
+         * My completely original solution on 10/23/2021.
+         */
+        public int findMin(int[] nums) {
+            int left = 0;
+            int right = nums.length - 1;
+            while (left < right) {
+                int mid = left + (right - left) / 2;
+                if (mid == left || mid == right) {
+                    //this is to avoid infinite loop
+                    break;
+                }
+                if (nums[mid] > nums[left] && nums[mid] > nums[right]) {
+                    left = mid + 1;
+                } else if (nums[mid] < nums[right] && nums[mid] > nums[left]) {
+                    right = mid - 1;
+                } else if (nums[mid] < nums[left] && nums[mid] < nums[right]) {
+                    right = mid;
+                }
+            }
+            return right >= 0 ? (nums[left] < nums[right] ? nums[left] : nums[right]) : nums[left];
         }
-      }
-      min = Math.min(min, Math.min(nums[left], nums[right]));
-      return min;
     }
-  }
 }
diff --git a/src/test/java/com/fishercoder/_153Test.java b/src/test/java/com/fishercoder/_153Test.java
@@ -7,45 +7,61 @@
 import static org.junit.Assert.assertEquals;
 
 public class _153Test {
-  private static _153.Solution1 solution1;
-  private static int expected;
-  private static int actual;
-  private static int[] nums;
-
-  @BeforeClass
-  public static void setup() {
-    solution1 = new _153.Solution1();
-  }
-
-  @Test
-  public void test1() {
-    nums = new int[] {4, 5, 6, 7, 0, 1, 2};
-    expected = 0;
-    actual = solution1.findMin(nums);
-    assertEquals(expected, actual);
-  }
-
-  @Test
-  public void test2() {
-    nums = new int[] {1};
-    expected = 1;
-    actual = solution1.findMin(nums);
-    assertEquals(expected, actual);
-  }
-
-  @Test
-  public void test3() {
-    nums = new int[] {2, 1};
-    expected = 1;
-    actual = solution1.findMin(nums);
-    assertEquals(expected, actual);
-  }
-
-  @Test
-  public void test4() {
-    nums = new int[] {2, 3, 4, 5, 1};
-    expected = 1;
-    actual = solution1.findMin(nums);
-    assertEquals(expected, actual);
-  }
+    private static _153.Solution1 solution1;
+    private static int expected;
+    private static int[] nums;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _153.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        nums = new int[]{4, 5, 6, 7, 0, 1, 2};
+        expected = 0;
+        assertEquals(expected, solution1.findMin(nums));
+    }
+
+    @Test
+    public void test2() {
+        nums = new int[]{1};
+        expected = 1;
+        assertEquals(expected, solution1.findMin(nums));
+    }
+
+    @Test
+    public void test3() {
+        nums = new int[]{2, 1};
+        expected = 1;
+        assertEquals(expected, solution1.findMin(nums));
+    }
+
+    @Test
+    public void test4() {
+        nums = new int[]{2, 3, 4, 5, 1};
+        expected = 1;
+        assertEquals(expected, solution1.findMin(nums));
+    }
+
+    @Test
+    public void test5() {
+        nums = new int[]{3, 1, 2};
+        expected = 1;
+        assertEquals(expected, solution1.findMin(nums));
+    }
+
+    @Test
+    public void test6() {
+        nums = new int[]{3, 4, 5, 1, 2};
+        expected = 1;
+        assertEquals(expected, solution1.findMin(nums));
+    }
+
+    @Test
+    public void test7() {
+        nums = new int[]{5, 1, 2, 3, 4};
+        expected = 1;
+        assertEquals(expected, solution1.findMin(nums));
+    }
 }
