Add solution and test-cases for problem 794

Author: 0xff-dev

leetcode/701-800/0794.Valid-Tic-Tac-Toe-State/1.jpg

@@ -1,28 +1,48 @@
 # [794.Valid Tic-Tac-Toe State][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
 
-**Example 1:**
+Given a Tic-Tac-Toe `board` as a string array board, return `true` if and only if it is possible to reach this board position during the course of a valid tic-tac-toe game.
+
+The board is a `3 x 3` array that consists of characters `' '`, `'X'`, and `'O'`. The `' '` character represents an empty square.
+
+Here are the rules of Tic-Tac-Toe:
+
+- Players take turns placing characters into empty squares `' '`.
+- The first player always places `'X'` characters, while the second player always places `'O'` characters.
+- `'X'` and `'O'` characters are always placed into empty squares, never filled ones.
+- The game ends when there are three of the same (non-empty) character filling any row, column, or diagonal.
+- The game also ends if all squares are non-empty.
+- No more moves can be played if the game is over.
+
+**Example 1:**  
+
+![1](./1.jpg)
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: board = ["O  ","   ","   "]
+Output: false
+Explanation: The first player always plays "X".
 ```
 
-## 题意
-> ...
+**Example 2:**  
 
-## 题解
+![2](./2.jpg)
 
-### 思路1
-> ...
-Valid Tic-Tac-Toe State
-```go
 ```
+Input: board = ["XOX"," X ","   "]
+Output: false
+Explanation: Players take turns making moves.
+```
+
+**Example 3:**  
+
+![3](./3.jpg)
 
+```
+Input: board = ["XOX","O O","XOX"]
+Output: true
+```
 
 ## 结语
 

leetcode/701-800/0794.Valid-Tic-Tac-Toe-State/2.jpg

@@ -1,5 +1,66 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func win794(board []string) (bool, bool) {
+	x, o := false, false
+	for i := range 3 {
+		if board[i][0] == board[i][1] && board[i][1] == board[i][2] {
+			if board[i][0] == 'X' {
+				x = true
+			}
+			if board[i][0] == 'O' {
+				o = true
+			}
+		}
+
+		if board[0][i] == board[1][i] && board[1][i] == board[2][i] {
+			if board[0][i] == 'X' {
+				x = true
+			}
+			if board[0][i] == 'O' {
+				o = true
+			}
+		}
+	}
+	if board[0][0] == board[1][1] && board[1][1] == board[2][2] {
+		if board[0][0] == 'X' {
+			x = true
+		}
+		if board[0][0] == 'O' {
+			o = true
+		}
+	}
+	if board[0][2] == board[1][1] && board[1][1] == board[2][0] {
+		if board[0][2] == 'X' {
+			x = true
+		}
+		if board[0][2] == 'O' {
+			o = true
+		}
+	}
+	return x, o
+}
+
+func Solution(board []string) bool {
+	xWin, oWin := win794(board)
+	if xWin && oWin {
+		return false
+	}
+	x, o := 0, 0
+	for i := range 3 {
+		for j := range 3 {
+			if board[i][j] == 'X' {
+				x++
+			}
+			if board[i][j] == 'O' {
+				o++
+			}
+		}
+	}
+	if !xWin && !oWin {
+		return x == o || x == o+1
+	}
+	if xWin {
+		return x == o+1
+	}
+	return x == o
 }

leetcode/701-800/0794.Valid-Tic-Tac-Toe-State/3.jpg

@@ -10,12 +10,12 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
+		inputs []string
 		expect bool
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []string{"O  ", "   ", "   "}, false},
+		{"TestCase2", []string{"XOX", " X ", "   "}, false},
+		{"TestCase3", []string{"XOX", "O O", "XOX"}, true},
 	}
 
 	//	开始测试
@@ -30,10 +30,10 @@ func TestSolution(t *testing.T) {
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }