add leetcode547

Author: saenaii

src/0547.Friend-Circles/Solution.go

@@ -0,0 +1,49 @@
+package Solution
+
+var p []int
+var r []int
+var ans int
+
+func findCircleNum(M [][]int) int {
+ ans = len(M)
+ initialize(ans)
+
+ for i := 0; i < len(M); i++ {
+ for j := 0; j < i; j++ {
+ if 1 == M[i][j] {
+ union(i, j)
+ }
+ }
+ }
+ return ans
+}
+
+func initialize(l int) {
+ p = make([]int, l)
+ r = make([]int, l)
+ for i, _ := range p {
+ p[i] = i
+ r[i] = 1
+ }
+}
+
+func find(x int) int {
+ if x != p[x] {
+ p[x] = find(p[x])
+ }
+ return p[x]
+}
+
+func union(x, y int) {
+ x, y = find(x), find(y)
+ if x != y {
+ if r[x] <= r[y] {
+ p[x] = y
+ r[y] += r[x]
+ } else {
+ p[y] = x
+ r[x] += r[y]
+ }
+ ans--
+ }
+}

src/0547.Friend-Circles/Solution_test.go

@@ -0,0 +1,44 @@
+package Solution
+
+import (
+"reflect"
+"testing"
+)
+
+func TestSolution(t *testing.T) {
+// 测试用例
+cases := []struct {
+name string
+inputs[][]int
+expect int
+}{
+{"TestCases 1",
+[][]int{
+{1,1,0},
+{1,1,1},
+{0,1,1},
+},
+1,
+},
+}
+
+// 开始测试
+for _, c := range cases {
+t.Run(c.name, func(t *testing.T) {
+got := findCircleNum(c.inputs)
+if !reflect.DeepEqual(got, c.expect) {
+t.Fatalf("expected: %v, but got: %v, with inputs: %v", c.expect, got, c.inputs)
+}
+})
+}
+}
+
+//	压力测试
+func BenchmarkSolution(b *testing.B) {
+
+}
+
+//	使用案列
+func ExampleSolution() {
+
+}

src/0547.Friend-Circles/readme.md

@@ -0,0 +1,95 @@
+# [547. Friend Circles][title]
+
+## Description
+
+There are N students in a class. Some of them are friends, while some are not. Their friendship is transitive in nature. For example, if A is a direct friend of B, and B is a direct friend of C, then A is an indirect friend of C. And we defined a friend circle is a group of students who are direct or indirect friends.
+
+Given a N*N matrix M representing the friend relationship between students in the class. If M[i][j] = 1, then the ith and jth students are direct friends with each other, otherwise not. And you have to output the total number of friend circles among all the students.
+
+**Example 1:**
+```
+Input: 
+[[1,1,0],
+ [1,1,0],
+ [0,0,1]]
+Output: 2
+Explanation:The 0th and 1st students are direct friends, so they are in a friend circle. 
+The 2nd student himself is in a friend circle. So return 2.
+```
+
+**Example 2:**
+```
+Input: 
+[[1,1,0],
+ [1,1,1],
+ [0,1,1]]
+Output: 1
+Explanation:The 0th and 1st students are direct friends, the 1st and 2nd students are direct friends, 
+so the 0th and 2nd students are indirect friends. All of them are in the same friend circle, so return 1.
+```
+
+## 题意
+> 判断几个学生是否在同一个圈子。
+
+## 题解
+
+### 思路 1
+> 使用并查集
+
+```go
+var p []int
+var r []int
+var ans int
+
+func findCircleNum(M [][]int) int {
+ ans = len(M)
+ initialize(ans)
+
+ for i := 0; i < len(M); i++ {
+ for j := 0; j < i; j++ {
+ if 1 == M[i][j] {
+ union(i, j)
+ }
+ }
+ }
+ return ans
+}
+
+func initialize(l int) {
+ p = make([]int, l)
+ r = make([]int, l)
+ for i, _ := range p {
+ p[i] = i
+ r[i] = 1
+ }
+ fmt.Println(p, r)
+}
+
+func find(x int) int {
+ if x != p[x] {
+ p[x] = find(p[x])
+ }
+ return p[x]
+}
+
+func union(x, y int) {
+ x, y = find(x), find(y)
+ if x != y {
+ if r[x] <= r[y] {
+ p[x] = y
+ r[y] += r[x]
+ } else {
+ p[y] = x
+ r[x] += r[y]
+ }
+ ans--
+ }
+}
+```
+
+## 结语
+
+如果你同我一样热爱数据结构、算法、LeetCode，可以关注我 GitHub 上的 LeetCode 题解：[awesome-golang-leetcode][me]
+
+[title]: https://leetcode.com/problems/friend-circles/description/
+[me]: https://github.com/kylesliu/awesome-golang-leetcode