feat: add the solution of Judge Route Circle(657) with Java.

Author: Mukyu

README.md

@@ -65,7 +65,7 @@
 | [643][643-question] | [Maximum Average Subarray I][643-tips]                       | [✅][643-java] | [✅][643-js] |                  |
 | [645][645-question] | [Set Mismatch][645-tips]                                     | [✅][645-java] | [✅][645-js] |                  |
 | [653][653-question] | [Two Sum IV - Input is a BST][653-tips]                      | [✅][653-java] | [✅][653-js] |                  |
-| [657][657-question] | [Judge Route Circle][657-tips]                               |                | [✅][657-js] |                  |
+| [657][657-question] | [Judge Route Circle][657-tips]                               | [✅][657-java] | [✅][657-js] |                  |
 | [661][661-question] | [Image Smoother][661-tips]                                   |                | [✅][661-js] |                  |
 | [665][665-question] | [Non-decreasing Array][665-tips]                             |                | [✅][665-js] |                  |
 | [669][669-question] | [Trim a Binary Search Tree][669-tips]                        |                | [✅][669-js] |                  |
@@ -456,6 +456,7 @@
 [643-java]: ./src/_643/Solution.java
 [645-java]: ./src/_645/Solution.java
 [653-java]: ./src/_653/Solution.java
+[657-java]: ./src/_657/Solution.java
 [728-java]: ./src/_728/Solution.java
 [771-java]: ./src/_771/Solution.java
 [804-java]: ./src/_804/Solution.java

src/_657/Solution.java

@@ -0,0 +1,11 @@
+package _657;
+
+class Solution {
+    public boolean judgeCircle(String moves) {
+        int[] count = new int[128];
+        for (char c : moves.toCharArray()) {
+            count[c]++;
+        }
+        return count['U'] == count['D'] && count['L'] == count['R'];
+    }
+}

tips/657/README.md

@@ -1,46 +1,45 @@
-[xxxx][title]
+[Judge Route Circle][title]
 
 ## Description
-// 抄题目
 
+Initially, there is a Robot at position (0, 0). Given a sequence of its moves, judge if this robot makes a circle, which means it moves back to **the original place**.
 
-**Example:**
+The move sequence is represented by a string. And each move is represent by a character. The valid robot moves are `R` (Right), `L`(Left), `U` (Up) and `D` (down). The output should be true or false representing whether the robot makes a circle.
+
+**Example 1:**
 
 ```
-// 抄Example
+Input: "UD"
+Output: true
 ```
 
-**Note:**
-// Note
-
-**Tags:** // tags
-
-
-## 思路 1
-// 贴一些关键代码,说一些解题思路
-// (同一种语言可以写多种思路，与某种语言思路相同的另一种语言的思路无须赘述，但可以把代码贴在后面) 
-```java
+**Example 2:**
 
 ```
-```javascript
-
+Input: "LL"
+Output: false
 ```
 
-## 思路 2
-// 贴一些关键代码,说一些解题思路
-```java
-
-```
+**Tags:** [String](https://leetcode.com/tag/string/)
 
-## 思路 3
-// 贴一些关键代码,说一些解题思路
-```kotlin
+## 思路
+如题意，机器人会按照所给指令`U`、`D`、`L`、`R`进行上下左右移动。题目要求根据所给指令，计算机器人是否能走回原点。遍历指令数组，分别记录`U`、`D`、`L`、`R`的个数，若U=D且L=R则能走回远点。
 
+```java
+class Solution {
+    public boolean judgeCircle(String moves) {
+        int[] count = new int[128];
+        for (char c : moves.toCharArray()) {
+            count[c]++;
+        }
+        return count['U'] == count['D'] && count['L'] == count['R'];
+    }
+}
 ```
 
 ## 结语
-   
+
 如果你同我们一样热爱数据结构、算法、LeetCode，可以关注我们 GitHub 上的 LeetCode 题解：[LeetCode-Solution][ls]
 
-[title]: https://leetcode.com/problems/xxxx
+[title]: https://leetcode.com/problems/judge-route-circle/description/
 [ls]: https://github.com/SDE603/LeetCode-Solution