feat: update solutions to lc problem: No.1812

No.1812.Determine Color of a Chessboard Square

Author: yanglbme

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

@@ -53,9 +53,11 @@
 
 <!-- 这里可写通用的实现逻辑 -->
 
-**方法一：奇偶判断**
+**方法一：找规律**
 
-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`。
+观察棋盘我们发现，颜色相同的两个格子 $(x_1, y_1)$ 和 $(x_2, y_2)$ 满足 $x_1 + y_1$ 和 $x_2 + y_2$ 均为奇数或偶数。
+
+因此，我们可以根据 `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 $O(1)$。
 
@@ -68,9 +70,7 @@
 ```python
 class Solution:
     def squareIsWhite(self, coordinates: str) -> bool:
-        x = ord(coordinates[0]) - ord('a') + 1
-        y = int(coordinates[1])
-        return ((x + y) & 1) == 1
+        return (ord(coordinates[0]) + ord(coordinates[1])) % 2 == 1
 ```
 
 ### **Java**
@@ -80,9 +80,7 @@ class Solution:
 ```java
 class Solution {
     public boolean squareIsWhite(String coordinates) {
-        int x = coordinates.charAt(0) - 'a' + 1;
-        int y = coordinates.charAt(1) - '0';
-        return ((x + y) & 1) == 1;
+        return (coordinates.charAt(0) + coordinates.charAt(1)) % 2 == 1; 
     }
 }
 ```
@@ -93,9 +91,7 @@ class Solution {
 class Solution {
 public:
     bool squareIsWhite(string coordinates) {
-        int x = coordinates[0] - 'a' + 1;
-        int y = coordinates[1] - '0';
-        return ((x + y) & 1) == 1;
+        return (coordinates[0] + coordinates[1]) % 2;
     }
 };
 ```
@@ -104,9 +100,7 @@ public:
 
 ```go
 func squareIsWhite(coordinates string) bool {
-	x := coordinates[0] - 'a' + 1
-	y := coordinates[1] - '0'
-	return ((x + y) & 1) == 1
+	return (coordinates[0]+coordinates[1])%2 == 1
 }
 ```
 
@@ -118,9 +112,9 @@ func squareIsWhite(coordinates string) bool {
  * @return {boolean}
  */
 var squareIsWhite = function (coordinates) {
-    const x = coordinates.charAt(0).charCodeAt() - 'a'.charCodeAt() + 1;
-    const y = Number(coordinates.charAt(1));
-    return ((x + y) & 1) == 1;
+    const x = coordinates.charAt(0).charCodeAt();
+    const y = coordinates.charAt(1).charCodeAt();
+    return (x + y) % 2 == 1;
 };
 ```
 

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

@@ -54,19 +54,15 @@
 ```python
 class Solution:
     def squareIsWhite(self, coordinates: str) -> bool:
-        x = ord(coordinates[0]) - ord('a') + 1
-        y = int(coordinates[1])
-        return ((x + y) & 1) == 1
+        return (ord(coordinates[0]) + ord(coordinates[1])) % 2 == 1
 ```
 
 ### **Java**
 
 ```java
 class Solution {
     public boolean squareIsWhite(String coordinates) {
-        int x = coordinates.charAt(0) - 'a' + 1;
-        int y = coordinates.charAt(1) - '0';
-        return ((x + y) & 1) == 1;
+        return (coordinates.charAt(0) + coordinates.charAt(1)) % 2 == 1; 
     }
 }
 ```
@@ -77,9 +73,7 @@ class Solution {
 class Solution {
 public:
     bool squareIsWhite(string coordinates) {
-        int x = coordinates[0] - 'a' + 1;
-        int y = coordinates[1] - '0';
-        return ((x + y) & 1) == 1;
+        return (coordinates[0] + coordinates[1]) % 2;
     }
 };
 ```
@@ -88,9 +82,7 @@ public:
 
 ```go
 func squareIsWhite(coordinates string) bool {
-	x := coordinates[0] - 'a' + 1
-	y := coordinates[1] - '0'
-	return ((x + y) & 1) == 1
+	return (coordinates[0]+coordinates[1])%2 == 1
 }
 ```
 
@@ -102,9 +94,9 @@ func squareIsWhite(coordinates string) bool {
  * @return {boolean}
  */
 var squareIsWhite = function (coordinates) {
-    const x = coordinates.charAt(0).charCodeAt() - 'a'.charCodeAt() + 1;
-    const y = Number(coordinates.charAt(1));
-    return ((x + y) & 1) == 1;
+    const x = coordinates.charAt(0).charCodeAt();
+    const y = coordinates.charAt(1).charCodeAt();
+    return (x + y) % 2 == 1;
 };
 ```
 

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

@@ -1,8 +1,6 @@
 class Solution {
 public:
     bool squareIsWhite(string coordinates) {
-        int x = coordinates[0] - 'a' + 1;
-        int y = coordinates[1] - '0';
-        return ((x + y) & 1) == 1;
+        return (coordinates[0] + coordinates[1]) % 2;
     }
 };

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

@@ -1,5 +1,3 @@
 func squareIsWhite(coordinates string) bool {
-	x := coordinates[0] - 'a' + 1
-	y := coordinates[1] - '0'
-	return ((x + y) & 1) == 1
+	return (coordinates[0]+coordinates[1])%2 == 1
 }

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

@@ -1,7 +1,5 @@
 class Solution {
     public boolean squareIsWhite(String coordinates) {
-        int x = coordinates.charAt(0) - 'a' + 1;
-        int y = coordinates.charAt(1) - '0';
-        return ((x + y) & 1) == 1;
+        return (coordinates.charAt(0) + coordinates.charAt(1)) % 2 == 1; 
     }
 }

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

@@ -3,7 +3,7 @@
  * @return {boolean}
  */
 var squareIsWhite = function (coordinates) {
-    const x = coordinates.charAt(0).charCodeAt() - 'a'.charCodeAt() + 1;
-    const y = Number(coordinates.charAt(1));
-    return ((x + y) & 1) == 1;
+    const x = coordinates.charAt(0).charCodeAt();
+    const y = coordinates.charAt(1).charCodeAt();
+    return (x + y) % 2 == 1;
 };

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

@@ -1,5 +1,3 @@
 class Solution:
     def squareIsWhite(self, coordinates: str) -> bool:
-        x = ord(coordinates[0]) - ord('a') + 1
-        y = int(coordinates[1])
-        return ((x + y) & 1) == 1
+        return (ord(coordinates[0]) + ord(coordinates[1])) % 2 == 1