Merge pull request #891 from 0xff-dev/1823

Add solution and test-cases for problem 1823

Author: 6boris

leetcode/1801-1900/1823.Find-the-Winner-of-the-Circular-Game/README.md

@@ -1,28 +1,44 @@
 # [1823.Find the Winner of the Circular Game][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
+There are `n` friends that are playing a game. The friends are sitting in a circle and are numbered from `1` to `n` in **clockwise order**. More formally, moving clockwise from the i<sup>th</sup> friend brings you to the `(i+1)`<sup>th</sup> friend for `1 <= i < n`, and moving clockwise from the n<sup>th</sup>. friend brings you to the 1<sup>st</sup> friend.
 
-**Example 1:**
+The rules of the game are as follows:
 
-```
-Input: a = "11", b = "1"
-Output: "100"
-```
+1. **Start** at the 1<sup>st</sup> friend.
+2. Count the next `k` friends in the clockwise direction **including** the friend you started at. The counting wraps around the circle and may count some friends more than once.
+3. The last friend you counted leaves the circle and loses the game.
+4. If there is still more than one friend in the circle, go back to step `2` **starting** from the friend **immediately clockwise** of the friend who just lost and repeat.
+5. Else, the last friend in the circle wins the game.
+
+Given the number of friends, `n`, and an integer `k`, return the winner of the game.
 
-## 题意
-> ...
+**Example 1:**  
 
-## 题解
+![1](./ic234-q2-ex11.png)
 
-### 思路1
-> ...
-Find the Winner of the Circular Game
-```go
 ```
+Input: n = 5, k = 2
+Output: 3
+Explanation: Here are the steps of the game:
+1) Start at friend 1.
+2) Count 2 friends clockwise, which are friends 1 and 2.
+3) Friend 2 leaves the circle. Next start is friend 3.
+4) Count 2 friends clockwise, which are friends 3 and 4.
+5) Friend 4 leaves the circle. Next start is friend 5.
+6) Count 2 friends clockwise, which are friends 5 and 1.
+7) Friend 1 leaves the circle. Next start is friend 3.
+8) Count 2 friends clockwise, which are friends 3 and 5.
+9) Friend 5 leaves the circle. Only friend 3 is left, so they are the winner.
+```
+
+**Example 2:**
 
+```
+Input: n = 6, k = 5
+Output: 1
+Explanation: The friends leave in this order: 5, 4, 6, 2, 3. The winner is friend 1.
+```
 
 ## 结语
 

leetcode/1801-1900/1823.Find-the-Winner-of-the-Circular-Game/Solution.go

@@ -1,5 +1,9 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(n int, k int) int {
+	winner := 0
+	for i := 2; i <= n; i++ {
+		winner = (winner + k) % i
+	}
+	return winner + 1
 }

leetcode/1801-1900/1823.Find-the-Winner-of-the-Circular-Game/Solution_test.go

@@ -10,30 +10,29 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		n, k   int
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", 5, 2, 3},
+		{"TestCase2", 6, 5, 1},
 	}
 
 	//	开始测试
 	for i, c := range cases {
 		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
-			got := Solution(c.inputs)
+			got := Solution(c.n, c.k)
 			if !reflect.DeepEqual(got, c.expect) {
-				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
-					c.expect, got, c.inputs)
+				t.Fatalf("expected: %v, but got: %v, with inputs: %v %v",
+					c.expect, got, c.n, c.k)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }