Add solution and test-cases for problem 2392

Author: 0xff-dev

leetcode/2301-2400/2392.Build-a-Matrix-With-Conditions/README.md

@@ -1,28 +1,47 @@
 # [2392.Build a Matrix With Conditions][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 **positive** integer `k`. You are also given:
 
-**Example 1:**
+- a 2D integer array `rowConditions` of size n where `rowConditions[i] = [abovei, belowi]`, and
+- a 2D integer array `colConditions` of size m where `colConditions[i] = [lefti, righti]`.
 
-```
-Input: a = "11", b = "1"
-Output: "100"
-```
+The two arrays contain integers from `1` to `k`.
+
+You have to build a `k x k` matrix that contains each of the numbers from `1` to `k` **exactly once**. The remaining cells should have the value `0`.
+
+The matrix should also satisfy the following conditions:
+
+- The number `abovei` should appear in a **row** that is strictly **above** the row at which the number `belowi` appears for all `i` from `0` to `n - 1`.
+- The number `lefti` should appear in a **column** that is strictly **left** of the column at which the number `righti` appears for all `i` from `0` to `m - 1`.
 
-## 题意
-> ...
+Return **any** matrix that satisfies the conditions. If no answer exists, return an empty matrix.
 
-## 题解
+**Example 1:**  
 
-### 思路1
-> ...
-Build a Matrix With Conditions
-```go
+![1](gridosdrawio.png)
+
+```
+Input: k = 3, rowConditions = [[1,2],[3,2]], colConditions = [[2,1],[3,2]]
+Output: [[3,0,0],[0,0,1],[0,2,0]]
+Explanation: The diagram above shows a valid example of a matrix that satisfies all the conditions.
+The row conditions are the following:
+- Number 1 is in row 1, and number 2 is in row 2, so 1 is above 2 in the matrix.
+- Number 3 is in row 0, and number 2 is in row 2, so 3 is above 2 in the matrix.
+The column conditions are the following:
+- Number 2 is in column 1, and number 1 is in column 2, so 2 is left of 1 in the matrix.
+- Number 3 is in column 0, and number 2 is in column 1, so 3 is left of 2 in the matrix.
+Note that there may be multiple correct answers.
 ```
 
+**Example 2:**
+
+```
+Input: k = 3, rowConditions = [[1,2],[2,3],[3,1],[2,3]], colConditions = [[2,1]]
+Output: []
+Explanation: From the first two conditions, 3 has to be below 1 but the third conditions needs 3 to be above 1 to be satisfied.
+No matrix can satisfy all the conditions, so we return the empty matrix.
+```
 
 ## 结语
 

leetcode/2301-2400/2392.Build-a-Matrix-With-Conditions/Solution.go

@@ -1,5 +1,66 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func sortConditions(k int, conditions [][]int) (map[int]int, bool) {
+	children := make(map[int][]int)
+	in := make(map[int]int)
+	for _, c := range conditions {
+		if _, ok := children[c[0]]; !ok {
+			children[c[0]] = make([]int, 0)
+		}
+		children[c[0]] = append(children[c[0]], c[1])
+		in[c[1]]++
+	}
+	index := 0
+	pos := make(map[int]int)
+	have := make([]int, 0)
+	left := k
+	for i := 1; i <= k; i++ {
+		if _, ok := in[i]; !ok {
+			pos[i] = index
+			have = append(have, i)
+			index++
+			left--
+		}
+	}
+	for left > 0 {
+		next := make([]int, 0)
+		for _, cur := range have {
+			for _, rel := range children[cur] {
+				in[rel]--
+				if in[rel] == 0 {
+					next = append(next, rel)
+					left--
+					pos[rel] = index
+					index++
+				}
+			}
+		}
+		if len(next) == 0 && left > 0 {
+			return nil, false
+		}
+		have = next
+	}
+	return pos, true
+}
+
+func Solution(k int, rowConditions [][]int, colConditions [][]int) [][]int {
+	ans := make([][]int, k)
+	for i := 0; i < k; i++ {
+		ans[i] = make([]int, k)
+	}
+	rowPos, ok := sortConditions(k, rowConditions)
+	if !ok {
+		return nil
+	}
+
+	colPos, ok := sortConditions(k, colConditions)
+	if !ok {
+		return nil
+	}
+
+	for i := 1; i <= k; i++ {
+		ans[rowPos[i]][colPos[i]] = i
+	}
+
+	return ans
 }

leetcode/2301-2400/2392.Build-a-Matrix-With-Conditions/Solution_test.go

@@ -9,31 +9,35 @@ import (
 func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
-		name   string
-		inputs bool
-		expect bool
+		name                         string
+		k                            int
+		rowConditions, colConditions [][]int
+		expect                       [][]int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", 3, [][]int{{1, 2}, {3, 2}}, [][]int{{2, 1}, {3, 2}}, [][]int{
+			{0, 0, 1},
+			{3, 0, 0},
+			{0, 2, 0},
+		}},
+		{"TestCase2", 3, [][]int{{1, 2}, {2, 3}, {3, 1}, {2, 3}}, [][]int{{2, 1}}, nil},
 	}
 
 	//	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.k, c.rowConditions, c.colConditions)
 			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.k, c.rowConditions, c.colConditions)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }