817 finish

Author: aQua

Algorithms/0817.linked-list-components/README.md

@@ -0,0 +1,42 @@
+# [817. Linked List Components](https://leetcode.com/problems/linked-list-components/)
+
+## 题目
+
+We are given head, the head node of a linked list containing unique integer values.
+
+We are also given the list G, a subset of the values in the linked list.
+
+Return the number of connected components in G, where two values are connected if they appear consecutively in the linked list.
+
+Example 1:
+
+```text
+Input:
+head: 0->1->2->3
+G = [0, 1, 3]
+Output: 2
+Explanation:
+0 and 1 are connected, so [0, 1] and [3] are the two connected components.
+```
+
+Example 2:
+
+```text
+Input:
+head: 0->1->2->3->4
+G = [0, 3, 1, 4]
+Output: 2
+Explanation:
+0 and 1 are connected, 3 and 4 are connected, so [0, 1] and [3, 4] are the two connected components.
+```
+
+Note:
+
+1. If N is the length of the linked list given by head, 1 <= N <= 10000.
+1. The value of each node in the linked list will be in the range [0, N - 1].
+1. 1 <= G.length <= 10000.
+1. G is a subset of all values in the linked list.
+
+## 解题思路
+
+见程序注释

Algorithms/0817.linked-list-components/linked-list-components.go

@@ -0,0 +1,75 @@
+package problem0817
+
+import (
+	"sort"
+
+	"github.com/aQuaYi/LeetCode-in-Go/kit"
+)
+
+/*
+ * Definition for singly-linked list.
+ * type ListNode struct {
+ *     Val int
+ *     Next *ListNode
+ * 	return 0
+}
+*/
+
+// ListNode is from kit
+type ListNode = kit.ListNode
+
+func numComponents(head *ListNode, G []int) int {
+	// 收集 list 中各个数的索引号
+	// 方便以后判断连通性
+	indexs := make(map[int]int, len(G)*2)
+	i := 0
+	for head != nil {
+		indexs[head.Val] = i
+		i++
+		head = head.Next
+	}
+
+	// 初步统计连通性
+	// temp[i][0] == 3 表示，第 i 个联通的链条 起点 是 3
+	// temp[i][1] == 5 表示，第 i 个联通的链条 终点 是 5
+	temp := make([][2]int, 0, len(G))
+	for _, num := range G {
+		idx := indexs[num]
+		isConnected := false
+		for i := range temp {
+			// 如果 idx 与 temp[i] 的 起点 相连
+			if idx+1 == temp[i][0] {
+				temp[i][0] = idx
+				isConnected = true
+				break
+			}
+			// 如果 idx 与 temp[i] 的 终点 相连
+			if temp[i][1] == idx-1 {
+				temp[i][1] = idx
+				isConnected = true
+				break
+			}
+		}
+		// 如果 idx 不与 temp 中的任何链条相连
+		if !isConnected {
+			temp = append(temp, [2]int{idx, idx})
+		}
+	}
+
+	// 按照链条的起点排序
+	sort.Slice(temp, func(i int, j int) bool {
+		return temp[i][0] < temp[j][0]
+	})
+
+	t := temp[0]
+	res := 1
+	for i := 1; i < len(temp); i++ {
+		// 如果前后两个链条不相连
+		if t[1]+1 != temp[i][0] {
+			res++
+		}
+		t = temp[i]
+	}
+
+	return res
+}

Algorithms/0817.linked-list-components/linked-list-components_test.go

@@ -0,0 +1,75 @@
+package problem0817
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/aQuaYi/LeetCode-in-Go/kit"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// tcs is testcase slice
+var tcs = []struct {
+	head []int
+	G    []int
+	ans  int
+}{
+
+	{
+		[]int{0, 2, 4, 3, 1},
+		[]int{3, 2, 4},
+		1,
+	},
+
+	{
+		[]int{1, 2, 0, 4, 3},
+		[]int{3, 4, 0, 2, 1},
+		1,
+	},
+
+	{
+		[]int{0, 1, 2},
+		[]int{1, 0, 2},
+		1,
+	},
+
+	{
+		[]int{0, 1, 2},
+		[]int{1, 0},
+		1,
+	},
+
+	{
+		[]int{0, 1, 2, 3},
+		[]int{0, 1, 3},
+		2,
+	},
+
+	{
+		[]int{0, 1, 2, 3, 4},
+		[]int{0, 3, 1, 4},
+		2,
+	},
+
+	// 可以有多个 testcase
+}
+
+func Test_numComponents(t *testing.T) {
+	ast := assert.New(t)
+
+	for _, tc := range tcs {
+		fmt.Printf("~~%v~~\n", tc)
+		head := kit.Ints2List(tc.head)
+		ast.Equal(tc.ans, numComponents(head, tc.G), "输入:%v", tc)
+	}
+}
+
+func Benchmark_numComponents(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		for _, tc := range tcs {
+			head := kit.Ints2List(tc.head)
+			numComponents(head, tc.G)
+		}
+	}
+}

leetcode.json

@@ -1,7 +1,7 @@
 {
 	"Username": "aQuaYi",
 	"Ranking": 1146,
-	"Updated": "2018-05-06T19:33:05.564465389+08:00",
+	"Updated": "2018-05-07T10:44:31.443065238+08:00",
 	"Record": {
 		"Easy": {
 			"Solved": 166,
@@ -2089,7 +2089,7 @@
 			"ID": 172,
 			"Title": "Factorial Trailing Zeroes",
 			"TitleSlug": "factorial-trailing-zeroes",
-			"PassRate": "36%",
+			"PassRate": "37%",
 			"Difficulty": "Easy",
 			"IsAccepted": true,
 			"IsPaid": false,
@@ -3901,7 +3901,7 @@
 			"ID": 323,
 			"Title": "Number of Connected Components in an Undirected Graph",
 			"TitleSlug": "number-of-connected-components-in-an-undirected-graph",
-			"PassRate": "48%",
+			"PassRate": "49%",
 			"Difficulty": "Medium",
 			"IsAccepted": false,
 			"IsPaid": true,
@@ -6421,7 +6421,7 @@
 			"ID": 533,
 			"Title": "Lonely Pixel II",
 			"TitleSlug": "lonely-pixel-ii",
-			"PassRate": "45%",
+			"PassRate": "44%",
 			"Difficulty": "Medium",
 			"IsAccepted": false,
 			"IsPaid": true,
@@ -8233,7 +8233,7 @@
 			"ID": 684,
 			"Title": "Redundant Connection",
 			"TitleSlug": "redundant-connection",
-			"PassRate": "44%",
+			"PassRate": "43%",
 			"Difficulty": "Medium",
 			"IsAccepted": true,
 			"IsPaid": false,
@@ -9001,7 +9001,7 @@
 			"ID": 748,
 			"Title": "Shortest Completing Word",
 			"TitleSlug": "shortest-completing-word",
-			"PassRate": "52%",
+			"PassRate": "51%",
 			"Difficulty": "Medium",
 			"IsAccepted": true,
 			"IsPaid": false,
@@ -9037,7 +9037,7 @@
 			"ID": 751,
 			"Title": "IP to CIDR",
 			"TitleSlug": "ip-to-cidr",
-			"PassRate": "55%",
+			"PassRate": "54%",
 			"Difficulty": "Easy",
 			"IsAccepted": false,
 			"IsPaid": true,
@@ -9565,7 +9565,7 @@
 			"ID": 795,
 			"Title": "Number of Subarrays with Bounded Maximum",
 			"TitleSlug": "number-of-subarrays-with-bounded-maximum",
-			"PassRate": "40%",
+			"PassRate": "41%",
 			"Difficulty": "Medium",
 			"IsAccepted": true,
 			"IsPaid": false,
@@ -9637,7 +9637,7 @@
 			"ID": 801,
 			"Title": "Minimum Swaps To Make Sequences Increasing",
 			"TitleSlug": "minimum-swaps-to-make-sequences-increasing",
-			"PassRate": "25%",
+			"PassRate": "26%",
 			"Difficulty": "Medium",
 			"IsAccepted": true,
 			"IsPaid": false,
@@ -9925,7 +9925,7 @@
 			"ID": 825,
 			"Title": "Friends Of Appropriate Ages",
 			"TitleSlug": "friends-of-appropriate-ages",
-			"PassRate": "24%",
+			"PassRate": "25%",
 			"Difficulty": "Medium",
 			"IsAccepted": false,
 			"IsPaid": false,
@@ -9961,7 +9961,7 @@
 			"ID": 828,
 			"Title": "Unique Letter String",
 			"TitleSlug": "unique-letter-string",
-			"PassRate": "24%",
+			"PassRate": "28%",
 			"Difficulty": "Hard",
 			"IsAccepted": false,
 			"IsPaid": false,
@@ -9973,7 +9973,7 @@
 			"ID": 829,
 			"Title": "Consecutive Numbers Sum",
 			"TitleSlug": "consecutive-numbers-sum",
-			"PassRate": "22%",
+			"PassRate": "23%",
 			"Difficulty": "Medium",
 			"IsAccepted": false,
 			"IsPaid": false,
@@ -9997,7 +9997,7 @@
 			"ID": 831,
 			"Title": "Masking Personal Information",
 			"TitleSlug": "masking-personal-information",
-			"PassRate": "42%",
+			"PassRate": "43%",
 			"Difficulty": "Medium",
 			"IsAccepted": false,
 			"IsPaid": false,