Add solution and test-cases for problem 3025

Author: 0xff-dev

leetcode/3001-3100/3025.Find-the-Number-of-Ways-to-Place-People-I/1.png

@@ -1,28 +1,60 @@
 # [3025.Find the Number of Ways to Place People I][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 2D array `points` of size `n x 2` representing integer coordinates of some points on a 2D plane, where `points[i] = [xi, yi]`.
+
+Count the number of pairs of points `(A, B)`, where
+
+- `A` is on the **upper left** side of `B`, and
+- there are no other points in the rectangle (or line) they make (**including the border**).
+
+Return the count.
+
+**Example 1:**  
 
-**Example 1:**
+![1](./1.png)
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: points = [[1,1],[2,2],[3,3]]
+
+Output: 0
+
+Explanation:
+
+There is no way to choose A and B so A is on the upper left side of B.
 ```
 
-## 题意
-> ...
+**Example 2:**  
 
-## 题解
+![2](./2.jpg)
 
-### 思路1
-> ...
-Find the Number of Ways to Place People I
-```go
 ```
+Input: points = [[6,2],[4,4],[2,6]]
+
+Output: 2
+
+Explanation:
 
+The left one is the pair (points[1], points[0]), where points[1] is on the upper left side of points[0] and the rectangle is empty.
+The middle one is the pair (points[2], points[1]), same as the left one it is a valid pair.
+The right one is the pair (points[2], points[0]), where points[2] is on the upper left side of points[0], but points[1] is inside the rectangle so it's not a valid pair.
+```
+
+**Example 3:**  
+
+![3](./3.jpg)
+
+```
+Input: points = [[3,1],[1,3],[1,1]]
+
+Output: 2
+
+Explanation:
+
+The left one is the pair (points[2], points[0]), where points[2] is on the upper left side of points[0] and there are no other points on the line they form. Note that it is a valid state when the two points form a line.
+The middle one is the pair (points[1], points[2]), it is a valid pair same as the left one.
+The right one is the pair (points[1], points[0]), it is not a valid pair as points[2] is on the border of the rectangle.
+```
 
 ## 结语
 

leetcode/3001-3100/3025.Find-the-Number-of-Ways-to-Place-People-I/2.jpg

@@ -1,5 +1,31 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(points [][]int) int {
+	ans := 0
+	l := len(points)
+	for i := 0; i < l; i++ {
+		for j := 0; j < l; j++ {
+			// 检查他俩是否ok
+			if i == j || !(points[i][0] <= points[j][0] && points[i][1] >= points[j][1]) {
+				// 不在左上角
+				continue
+			}
+			k := 0
+			for ; k < l; k++ {
+				if k == i || k == j {
+					continue
+				}
+				x := points[k][0] <= points[j][0] && points[k][0] >= points[i][0]
+				y := points[k][1] >= points[j][1] && points[k][1] <= points[i][1]
+				if x && y {
+					break
+				}
+			}
+			if k == l {
+				ans++
+			}
+
+		}
+	}
+	return ans
 }

leetcode/3001-3100/3025.Find-the-Number-of-Ways-to-Place-People-I/3.jpg

@@ -10,12 +10,12 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs [][]int
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", [][]int{{1, 1}, {2, 2}, {3, 3}}, 0},
+		{"TestCase2", [][]int{{6, 2}, {4, 4}, {2, 6}}, 2},
+		{"TestCase3", [][]int{{3, 1}, {1, 3}, {1, 1}}, 2},
 	}
 
 	//	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() {
 }