feat: update solutions to lc problems

* No.1812.Determine Color of a Chessboard Square
* No.2491.Divide Players Into Teams of Equal Skill
* No.2493.Divide Nodes Into the Maximum Number of Groups

Author: yanglbme

solution/1800-1899/1805.Number of Different Integers in a String/README.md

@@ -54,11 +54,11 @@
 
 **方法一：双指针 + 模拟**
 
-遍历字符串，找到每个整数的起始位置和结束位置，截取出这一个子串，将其存入哈希表 `s` 中。
+遍历字符串 `word`，找到每个整数的起始位置和结束位置，截取出这一个子串，将其存入哈希表 $s$ 中。
 
-最后返回哈希表 `s` 的大小即可。
+遍历结束，返回哈希表 $s$ 的大小即可。
 
-注意，这里要去掉整数的前导零，并且不能直接将字符串转为整数，因为整数可能很大，超出 `int` 的范围。
+> 注意，每个子串所表示的整数可能很大，我们不能直接将其转为整数。因此，我们可以去掉每个子串的前导零之后，再存入哈希表。
 
 时间复杂度 $O(n)$，空间复杂度 $O(n)$。其中 $n$ 为字符串 `word` 的长度。
 
@@ -123,13 +123,9 @@ public:
         int n = word.size();
         for (int i = 0; i < n; ++i) {
             if (isdigit(word[i])) {
-                while (i < n && word[i] == '0') {
-                    ++i;
-                }
+                while (i < n && word[i] == '0') ++i;
                 int j = i;
-                while (j < n && isdigit(word[j])) {
-                    ++j;
-                }
+                while (j < n && isdigit(word[j])) ++j;
                 s.insert(word.substr(i, j - i));
                 i = j;
             }

solution/1800-1899/1805.Number of Different Integers in a String/README_EN.md

@@ -104,13 +104,9 @@ public:
         int n = word.size();
         for (int i = 0; i < n; ++i) {
             if (isdigit(word[i])) {
-                while (i < n && word[i] == '0') {
-                    ++i;
-                }
+                while (i < n && word[i] == '0') ++i;
                 int j = i;
-                while (j < n && isdigit(word[j])) {
-                    ++j;
-                }
+                while (j < n && isdigit(word[j])) ++j;
                 s.insert(word.substr(i, j - i));
                 i = j;
             }

solution/1800-1899/1805.Number of Different Integers in a String/Solution.cpp

@@ -5,13 +5,9 @@ class Solution {
         int n = word.size();
         for (int i = 0; i < n; ++i) {
             if (isdigit(word[i])) {
-                while (i < n && word[i] == '0') {
-                    ++i;
-                }
+                while (i < n && word[i] == '0') ++i;
                 int j = i;
-                while (j < n && isdigit(word[j])) {
-                    ++j;
-                }
+                while (j < n && isdigit(word[j])) ++j;
                 s.insert(word.substr(i, j - i));
                 i = j;
             }

solution/1800-1899/1812.Determine Color of a Chessboard Square/README.md

@@ -53,6 +53,12 @@
 
 <!-- 这里可写通用的实现逻辑 -->
 
+**方法一：奇偶判断**
+
+根据 `coordinates` 获取对应的坐标 $(x, y)$，如果 $(x + y)$ 为奇数，则格子为白色，返回 `true`，否则返回 `false`。
+
+时间复杂度 $O(1)$。
+
 <!-- tabs:start -->
 
 ### **Python3**
@@ -81,6 +87,29 @@ class Solution {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    bool squareIsWhite(string coordinates) {
+        int x = coordinates[0] - 'a' + 1;
+        int y = coordinates[1] - '0';
+        return ((x + y) & 1) == 1;
+    }
+};
+```
+
+### **Go**
+
+```go
+func squareIsWhite(coordinates string) bool {
+	x := coordinates[0] - 'a' + 1
+	y := coordinates[1] - '0'
+	return ((x + y) & 1) == 1
+}
+```
+
 ### **JavaScript**
 
 ```js
@@ -89,8 +118,8 @@ class Solution {
  * @return {boolean}
  */
 var squareIsWhite = function (coordinates) {
-    let x = coordinates.charAt(0).charCodeAt() - 'a'.charCodeAt() + 1;
-    let y = Number(coordinates.charAt(1));
+    const x = coordinates.charAt(0).charCodeAt() - 'a'.charCodeAt() + 1;
+    const y = Number(coordinates.charAt(1));
     return ((x + y) & 1) == 1;
 };
 ```

solution/1800-1899/1812.Determine Color of a Chessboard Square/README_EN.md

@@ -71,6 +71,29 @@ class Solution {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    bool squareIsWhite(string coordinates) {
+        int x = coordinates[0] - 'a' + 1;
+        int y = coordinates[1] - '0';
+        return ((x + y) & 1) == 1;
+    }
+};
+```
+
+### **Go**
+
+```go
+func squareIsWhite(coordinates string) bool {
+	x := coordinates[0] - 'a' + 1
+	y := coordinates[1] - '0'
+	return ((x + y) & 1) == 1
+}
+```
+
 ### **JavaScript**
 
 ```js
@@ -79,8 +102,8 @@ class Solution {
  * @return {boolean}
  */
 var squareIsWhite = function (coordinates) {
-    let x = coordinates.charAt(0).charCodeAt() - 'a'.charCodeAt() + 1;
-    let y = Number(coordinates.charAt(1));
+    const x = coordinates.charAt(0).charCodeAt() - 'a'.charCodeAt() + 1;
+    const y = Number(coordinates.charAt(1));
     return ((x + y) & 1) == 1;
 };
 ```

solution/1800-1899/1812.Determine Color of a Chessboard Square/Solution.cpp

@@ -0,0 +1,8 @@
+class Solution {
+public:
+    bool squareIsWhite(string coordinates) {
+        int x = coordinates[0] - 'a' + 1;
+        int y = coordinates[1] - '0';
+        return ((x + y) & 1) == 1;
+    }
+};

solution/1800-1899/1812.Determine Color of a Chessboard Square/Solution.go

@@ -0,0 +1,5 @@
+func squareIsWhite(coordinates string) bool {
+	x := coordinates[0] - 'a' + 1
+	y := coordinates[1] - '0'
+	return ((x + y) & 1) == 1
+}

solution/1800-1899/1812.Determine Color of a Chessboard Square/Solution.js

@@ -3,7 +3,7 @@
  * @return {boolean}
  */
 var squareIsWhite = function (coordinates) {
-    let x = coordinates.charAt(0).charCodeAt() - 'a'.charCodeAt() + 1;
-    let y = Number(coordinates.charAt(1));
+    const x = coordinates.charAt(0).charCodeAt() - 'a'.charCodeAt() + 1;
+    const y = Number(coordinates.charAt(1));
     return ((x + y) & 1) == 1;
 };

solution/2400-2499/2490.Circular Sentence/README.md

@@ -207,7 +207,6 @@ impl Solution {
 }
 ```
 
-
 ### **...**
 
 ```

solution/2400-2499/2490.Circular Sentence/Solution.js

@@ -1,4 +1,4 @@
-var isCircularSentence = function(sentence) {
+var isCircularSentence = function (sentence) {
     const words = sentence.split(' ');
     const post = words[0].charCodeAt(0);
     let prev = words[0].charCodeAt(words[0].length - 1);
@@ -11,4 +11,4 @@ var isCircularSentence = function(sentence) {
         prev = cur.charCodeAt(cur.length - 1);
     }
     return post === prev;
-};
+};