Add solution and test-cases for problem 1583

leetcode/1501-1600/1583.Count-Unhappy-Friends/README.md

@@ -1,28 +1,48 @@
 # [1583.Count Unhappy Friends][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 a list of `preferences` for n friends, where n is always **even**.
+
+For each person `i`, `preferences[i]` contains a list of friends **sorted** in the **order of preference**. In other words, a friend earlier in the list is more preferred than a friend later in the list. Friends in each list are denoted by integers from `0` to `n-1`.
+
+All the friends are divided into pairs. The pairings are given in a list `paris`, where `pairs[i] = [xi, yi]` denotes `xi` is paired with `yi` and `yi` is paired with `xi`.
+
+However, this pairing may cause some of the friends to be unhappy. A friend `x` is unhappy if `x` is paired with `y` and there exists a friend `u` who is paired with `v` but:
+
+- `x` prefers `u` over `y`, and
+- `u` prefers `x` over `v`.
+
+Return the number of unhappy friends.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: n = 4, preferences = [[1, 2, 3], [3, 2, 0], [3, 1, 0], [1, 2, 0]], pairs = [[0, 1], [2, 3]]
+Output: 2
+Explanation:
+Friend 1 is unhappy because:
+- 1 is paired with 0 but prefers 3 over 0, and
+- 3 prefers 1 over 2.
+Friend 3 is unhappy because:
+- 3 is paired with 2 but prefers 1 over 2, and
+- 1 prefers 3 over 0.
+Friends 0 and 2 are happy.
 ```
 
-## 题意
-> ...
+**Example 2:**
 
-## 题解
-
-### 思路1
-> ...
-Count Unhappy Friends
-```go
 ```
+Input: n = 2, preferences = [[1], [0]], pairs = [[1, 0]]
+Output: 0
+Explanation: Both friends 0 and 1 are happy.
+```
+
+**Example 3:**
 
+```
+Input: n = 4, preferences = [[1, 3, 2], [2, 3, 0], [1, 3, 0], [0, 2, 1]], pairs = [[1, 3], [0, 2]]
+Output: 4
+```
 
 ## 结语
 

leetcode/1501-1600/1583.Count-Unhappy-Friends/Solution.go

@@ -1,5 +1,45 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(n int, preferences [][]int, pairs [][]int) int {
+	likeIndex := make([]map[int]int, len(preferences))
+	for i, p := range preferences {
+		likeIndex[i] = make(map[int]int)
+		for idx, like := range p {
+			likeIndex[i][like] = idx
+		}
+	}
+
+	pair := make(map[int]int)
+	for _, p := range pairs {
+		pair[p[0]] = p[1]
+		pair[p[1]] = p[0]
+	}
+	var ret int
+	for _, p := range pairs {
+		x, y := p[0], p[1]
+		for _, u := range preferences[x] {
+			if u == y {
+				break
+			}
+			if v, ok := pair[u]; ok {
+				if likeIndex[u][x] < likeIndex[u][v] {
+					ret++
+					break
+				}
+			}
+		}
+
+		for _, u := range preferences[y] {
+			if u == x {
+				break
+			}
+			if v, ok := pair[u]; ok {
+				if likeIndex[u][y] < likeIndex[u][v] {
+					ret++
+					break
+				}
+			}
+		}
+	}
+	return ret
 }

leetcode/1501-1600/1583.Count-Unhappy-Friends/Solution_test.go

@@ -9,31 +9,41 @@ import (
 func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
-		name   string
-		inputs bool
-		expect bool
+		name        string
+		n           int
+		preferences [][]int
+		pairs       [][]int
+		expect      int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", 4, [][]int{
+			{1, 2, 3}, {3, 2, 0}, {3, 1, 0}, {1, 2, 0},
+		}, [][]int{
+			{0, 1}, {2, 3},
+		}, 2},
+		{"TestCase2", 2, [][]int{
+			{1}, {0},
+		}, [][]int{{1, 0}}, 0},
+		{"TestCase3", 4, [][]int{
+			{1, 3, 2}, {2, 3, 0}, {1, 3, 0}, {0, 2, 1},
+		}, [][]int{{1, 3}, {0, 2}}, 4},
 	}
 
 	//	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.preferences, c.pairs)
 			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 %v",
+					c.expect, got, c.n, c.preferences, c.pairs)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }