feat: create sync actions

添加 GitHub Actions，实现仓库内容自动同步至 Gitee，并部署到 Gitee Pages

Author: yanglbme

.github/workflows/gradle.yml

@@ -10,7 +10,7 @@ jobs:
     name: Algorithms Test
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest]
         java-version: [1.8]
     runs-on: ${{ matrix.os }}
 

.github/workflows/sync.yml

@@ -0,0 +1,26 @@
+name: Sync
+
+on:
+  push:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+        
+    - name: Sync to Gitee
+      uses: wearerequired/git-mirror-action@master
+      env:
+          SSH_PRIVATE_KEY: ${{ secrets.GITEE_RSA_PRIVATE_KEY }}
+      with:
+          source-repo: "git@github.com:doocs/data-structure-and-algorithm.git"
+          destination-repo: "git@gitee.com:Doocs/data-structure-and-algorithm.git"
+          
+    - name: Rebuild Gitee Pages
+      uses: mizuka-wu/gitee-pages-action@v1.0.0
+      with:
+          repository: doocs/data-structure-and-algorithm
+          cookie: ${{ secrets.GITEE_COOKIE }}
+          branch: master

src/main/java/array/DynamicArray.java

@@ -136,9 +136,31 @@ public E remove(int index) {
             elements[i - 1] = elements[i];
         }
         elements[--size] = null;
+
+        // 裁剪数组
+        trim();
+
         return oldElement;
     }
 
+    /**
+     * 数组缩容
+     */
+    private void trim() {
+        int capacity = elements.length;
+        if (size >= (capacity >> 1) || capacity <= DEFAULT_CAPACITY) {
+            // 不进行缩容
+            return;
+        }
+
+        // 缩容
+        int newCapacity = capacity >> 1;
+        E[] newElements = (E[]) new Object[newCapacity];
+        System.arraycopy(elements, 0, newElements, 0, size);
+        elements = newElements;
+
+    }
+
     /**
      * 清空数组
      */