Several bug fixes and improvements (#945)

* Update Dockerfile for code debugging.

* Format Python code using Black.

* Improve dark theme by defining html classes for the figures, animations and cover images.

* Fix several glossary translation.

* Update a code comment.

* Fix climbing_stairs_backtrack: the pruning should not require the sorted choices list.

* Update the code of array and list traversal.

* Fix a rendering issue of README.md

* Update code of list traversal.

* Fix array_definition.png

* Update README.md

* Fix max_capacity_moving_short_board.png

* Fix array.dart

* Fix array.dart

* Fix array.dart

* Fix array.dart

codes/cpp/chapter_array_and_linkedlist/array.cpp

@@ -52,7 +52,7 @@ void traverse(int *nums, int size) {
     int count = 0;
     // 通过索引遍历数组
     for (int i = 0; i < size; i++) {
-        count++;
+        count += nums[i];
     }
 }
 

codes/cpp/chapter_array_and_linkedlist/list.cpp

@@ -14,8 +14,8 @@ int main() {
     printVector(nums);
 
     /* 访问元素 */
-    int x = nums[1];
-    cout << "访问索引 1 处的元素，得到 x = " << x << endl;
+    int num = nums[1];
+    cout << "访问索引 1 处的元素，得到 num = " << num << endl;
 
     /* 更新元素 */
     nums[1] = 0;
@@ -49,13 +49,12 @@ int main() {
     /* 通过索引遍历列表 */
     int count = 0;
     for (int i = 0; i < nums.size(); i++) {
-        count++;
+        count += nums[i];
     }
-
     /* 直接遍历列表元素 */
     count = 0;
-    for (int n : nums) {
-        count++;
+    for (int x : nums) {
+        count += x;
     }
 
     /* 拼接两个列表 */

codes/cpp/chapter_dynamic_programming/climbing_stairs_backtrack.cpp

@@ -16,7 +16,7 @@ void backtrack(vector<int> &choices, int state, int n, vector<int> &res) {
     for (auto &choice : choices) {
         // 剪枝：不允许越过第 n 阶
         if (state + choice > n)
-            break;
+            continue;
         // 尝试：做出选择，更新状态
         backtrack(choices, state + choice, n, res);
         // 回退