Create DynamicArrayTest.java

src/main/java/com/nbee/solution/practice/BinarySearch.java

@@ -91,6 +91,7 @@ class BinarySearch {
         return candidate;
     }
 
+    //改进二分查找
     public static int binarySearchLeftMost0(int[] nums, int target) {
         int i = 0, j = nums.length - 1;
         while (i <= j) {
@@ -116,4 +117,25 @@ class BinarySearch {
         }
         return i - 1;
     }
+
+    /**
+     * 给你一个按照非递减顺序排列的整数数组 nums，和一个目标值 target。请你找出给定目标值在数组中的开始位置和结束位置。
+     * 如果数组中不存在目标值 target，返回 [-1, -1]。
+     * 你必须设计并实现时间复杂度为 O(log n) 的算法解决此问题。
+     *
+     * @param nums
+     * @param target
+     * @return
+     */
+    public static int[] searchRange(int[] nums, int target) {
+        if (nums.length == 0){
+            return new int[]{-1,-1};
+        }
+        if (nums.length == 1){
+            return new int[]{0,0};
+        }
+        int left = binarySearchLeftMost(nums, target);
+        int right = binarySearchRightMost(nums,target);
+        return new int[]{left,right};
+    }
 }

src/main/java/com/nbee/solution/practice/DynamicArray.java

@@ -0,0 +1,33 @@
+package com.nbee.solution.practice;
+
+public class DynamicArray {
+    private int size = 0;
+    private int capacity = 8;
+    private int[] array = new int[capacity];
+
+    public void addList(int element) {
+        add(size, element);
+    }
+
+    public void add(int index, int element) {
+        if (index < 0 || index > size){
+            throw new IndexOutOfBoundsException();
+        }
+        if (index >= 0 && index < size) {
+            System.arraycopy(array, index, array, index + 1, size - index);
+        }
+        array[index] = element;
+        size++;
+    }
+
+    public int getSize() {
+        return size;
+    }
+    public int get(int index) {
+        if (index < 0 || index >= size){
+            throw new IndexOutOfBoundsException();
+        }
+        return array[index];
+    }
+}
+

src/test/java/com/nbee/solution/practice/BinarySearchTest.java

@@ -97,18 +97,18 @@ public class BinarySearchTest {
         int result = Arrays.binarySearch(nums, target);
         if (result < 0) {
             int insertIndex = Math.abs(result + 1);
-            System.out.printf("nums: " + Arrays.toString(nums) + "\n");
-            System.out.printf("insertIndex: " + insertIndex + "\n");
+            System.out.println("nums: " + Arrays.toString(nums));
+            System.out.println("insertIndex: " + insertIndex);
             int[] newNums = new int[nums.length + 1];
             //第一次拷贝
             System.arraycopy(nums, 0, newNums, 0, nums.length);
-            System.out.printf("newNums: " + Arrays.toString(newNums) + "\n");
+            System.out.println("newNums: " + Arrays.toString(newNums));
             newNums[insertIndex] = target;
             // 第二次拷贝
             System.arraycopy(nums, insertIndex, newNums, insertIndex + 1, nums.length - insertIndex);
-            System.out.printf("newNums: " + Arrays.toString(newNums) + "\n");
+            System.out.println("newNums: " + Arrays.toString(newNums));
         }
-        System.out.printf("result: " + result);
+        System.out.println("result: " + result);
         assertEquals(-3, result, "The target should not be found");
     }
 
@@ -126,4 +126,14 @@ public class BinarySearchTest {
         assertEquals(2, BinarySearch.binarySearchRightMost(nums, 3));
         assertEquals(7, BinarySearch.binarySearchRightMost(nums, 5));
     }
+
+    @Test
+    public void testSearchRange() {
+        int[] nums = {5, 7, 7, 8, 8, 10};
+        int[] nums1 = {1};
+        assertArrayEquals(new int[]{1,2}, BinarySearch.searchRange(nums, 7), "The result should be [1, 2]" );
+        assertArrayEquals(new int[]{3,4}, BinarySearch.searchRange(nums, 8), "The result should be [3, 4]" );
+        assertArrayEquals(new int[]{-1, -1}, BinarySearch.searchRange(nums, 6), "The result should be [-1, -1]");
+        assertArrayEquals(new int[]{0, 0}, BinarySearch.searchRange(nums1, 1), "The result should be [0, 0]");
+    }
 }

src/test/java/com/nbee/solution/practice/DynamicArrayTest.java

@@ -0,0 +1,44 @@
+package com.nbee.solution.practice;
+
+import org.junit.Assert;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+class DynamicArrayTest {
+
+    private DynamicArray dynamicArray;
+
+    @BeforeEach
+    void setUp() {
+        dynamicArray = new DynamicArray();
+    }
+
+    @Test
+    void testAddListInitial() {
+        dynamicArray.addList(1);
+        dynamicArray.addList(3);
+        dynamicArray.addList(5);
+        for (int i = 0; i < 3; i++){
+            System.out.println(dynamicArray.get(i));
+        }
+    }
+
+
+    @Test
+    void testAddListMultiple() {
+        dynamicArray.addList(2);
+        dynamicArray.addList(3);
+        dynamicArray.addList(4);
+        assertEquals(3, dynamicArray.getSize(), "Size should be 3 after adding three elements.");
+    }
+
+    @Test
+    void testAddListCapacityExceeded() {
+        for (int i = 0; i < 8; i++) {
+            dynamicArray.addList(i);
+        }
+        assertEquals(8, dynamicArray.getSize(), "Size should be 8 after adding elements up to capacity.");
+    }
+
+}