Merge pull request #1194 from 0xff-dev/822

Add solution and test-cases for problem 822

Author: 6boris

leetcode/801-900/0822.Card-Flipping-Game/README.md

@@ -1,28 +1,31 @@
 # [822.Card Flipping 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
+You are given two **0-indexed** integer arrays `fronts` and `backs` of length `n`, where the `ith` card has the positive integer `fronts[i]` printed on the front and `backs[i]` printed on the back. Initially, each card is placed on a table such that the front number is facing up and the other is facing down. You may flip over any number of cards (possibly zero).
+
+After flipping the cards, an integer is considered *8good** if it is facing down on some card and **not** facing up on any card.
+
+Return the minimum possible good integer after flipping the cards. If there are no good integers, return `0`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: fronts = [1,2,4,4,7], backs = [1,3,4,1,3]
+Output: 2
+Explanation:
+If we flip the second card, the face up numbers are [1,3,4,4,7] and the face down are [1,2,4,1,3].
+2 is the minimum good integer as it appears facing down but not facing up.
+It can be shown that 2 is the minimum possible good integer obtainable after flipping some cards.
 ```
 
-## 题意
-> ...
+**Example 2:**
 
-## 题解
-
-### 思路1
-> ...
-Card Flipping Game
-```go
 ```
-
+Input: fronts = [1], backs = [1]
+Output: 0
+Explanation:
+There are no good integers no matter how we flip the cards, so we return 0.
+```
 
 ## 结语
 

leetcode/801-900/0822.Card-Flipping-Game/Solution.go

@@ -1,5 +1,41 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(fronts []int, backs []int) int {
+	fm := make(map[int]struct{})
+	for _, n := range fronts {
+		fm[n] = struct{}{}
+	}
+	ans := 0
+	for _, n := range backs {
+		if _, ok := fm[n]; !ok {
+			if ans == 0 || ans > n {
+				ans = n
+			}
+		}
+	}
+	mm := make(map[int][]int)
+	keys := make([]int, 0)
+	for i, f := range fronts {
+		if _, ok := mm[f]; !ok {
+			mm[f] = make([]int, 0)
+			keys = append(keys, f)
+		}
+		mm[f] = append(mm[f], backs[i])
+	}
+	for i := 0; i < len(keys); i++ {
+		ok := true
+		for _, v := range mm[keys[i]] {
+			if v == keys[i] {
+				ok = false
+				break
+			}
+		}
+		if !ok {
+			continue
+		}
+		if ans == 0 || ans > keys[i] {
+			ans = keys[i]
+		}
+	}
+	return ans
 }

leetcode/801-900/0822.Card-Flipping-Game/Solution_test.go

@@ -9,31 +9,30 @@ import (
 func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
-		name   string
-		inputs bool
-		expect bool
+		name          string
+		fronts, backs []int
+		expect        int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{1, 2, 4, 4, 7}, []int{1, 3, 4, 1, 3}, 2},
+		{"TestCase2", []int{1}, []int{1}, 0},
 	}
 
 	//	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.fronts, c.backs)
 			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.fronts, c.backs)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }