Add solution and test-cases for problem 436

leetcode/401-500/0436.Find-Right-Interval/README.md

@@ -1,28 +1,38 @@
 # [436.Find Right Interval][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 an array of `intervals`, where `intervals[i] = [starti, endi]` and each `starti` is **unique**.
+
+The **right interval** for an interval `i` is an interval `j` such that `startj >= endi` and `startj` is **minimized**. Note that `i` may equal `j`.
+
+Return an array of **right interval** indices for each interval `i`. If no **right interval** exists for interval `i`, then put `-1` at index `i`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: intervals = [[1,2]]
+Output: [-1]
+Explanation: There is only one interval in the collection, so it outputs -1.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Find Right Interval
-```go
 ```
+Input: intervals = [[3,4],[2,3],[1,2]]
+Output: [-1,0,1]
+Explanation: There is no right interval for [3,4].
+The right interval for [2,3] is [3,4] since start0 = 3 is the smallest start that is >= end1 = 3.
+The right interval for [1,2] is [2,3] since start1 = 2 is the smallest start that is >= end2 = 2.
+```
+
+**Example 3:**
 
+```
+Input: intervals = [[1,4],[2,3],[3,4]]
+Output: [-1,2,-1]
+Explanation: There is no right interval for [1,4] and [3,4].
+The right interval for [2,3] is [3,4] since start2 = 3 is the smallest start that is >= end1 = 3.
+```
 
 ## 结语
 

leetcode/401-500/0436.Find-Right-Interval/Solution.go

@@ -1,5 +1,61 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import (
+	"fmt"
+	"sort"
+)
+
+func Solution(intervals [][]int) []int {
+	l := len(intervals)
+	ans := make([]int, 0)
+	inCopy := make([][]int, l)
+	ai := make(map[string]int)
+	bi := make(map[string]int)
+
+	for i := 0; i < l; i++ {
+		inCopy[i] = make([]int, 2)
+		copy(inCopy[i], intervals[i])
+		k := fmt.Sprintf("%d-%d", intervals[i][0], intervals[i][1])
+		ai[k] = i
+	}
+
+	sort.Slice(inCopy, func(i, j int) bool {
+		if inCopy[i][0] == inCopy[j][0] {
+			return inCopy[i][1] < inCopy[j][1]
+		}
+		return inCopy[i][0] < inCopy[j][0]
+	})
+	for i := 0; i < l; i++ {
+		k := fmt.Sprintf("%d-%d", inCopy[i][0], inCopy[i][1])
+		bi[k] = i
+	}
+
+	var bsearch func(int, int, int) int
+	bsearch = func(left, right, target int) int {
+		ll, r := left, right
+		for ll < r {
+			mid := ll + (r-ll)/2
+			if inCopy[mid][0] < target {
+				ll = mid + 1
+				continue
+			}
+			r = mid
+		}
+		if ll == right || r == left {
+			return -1
+		}
+		k := fmt.Sprintf("%d-%d", inCopy[r][0], inCopy[r][1])
+		return ai[k]
+	}
+
+	for idx, in := range intervals {
+		k := fmt.Sprintf("%d-%d", in[0], in[1])
+		if in[0] == in[1] {
+			ans = append(ans, idx)
+			continue
+		}
+		left := bi[k]
+		ans = append(ans, bsearch(left, l, in[1]))
+	}
+	return ans
 }

leetcode/401-500/0436.Find-Right-Interval/Solution_test.go

@@ -10,12 +10,13 @@ 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, 2}}, []int{-1}},
+		{"TestCase2", [][]int{{3, 4}, {2, 3}, {1, 2}}, []int{-1, 0, 1}},
+		{"TestCase3", [][]int{{1, 4}, {2, 3}, {3, 4}}, []int{-1, 2, -1}},
+		{"TestCase4", [][]int{{1, 1}, {3, 4}}, []int{0, -1}},
 	}
 
 	//	开始测试
@@ -30,10 +31,10 @@ 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() {
 }