Merge pull request youngyangyang04#2651 from huaxulong/master

0098.所有可达路径增加Go解法

Author: youngyangyang04

problems/kamacoder/0098.所有可达路径.md

@@ -605,6 +605,125 @@ if __name__ == "__main__":
 ```
 ### Go
 
+#### 邻接矩阵写法
+```go
+package main
+
+import (
+	"fmt"
+)
+
+var result [][]int // 收集符合条件的路径
+var path []int     // 1节点到终点的路径
+
+func dfs(graph [][]int, x, n int) {
+	// 当前遍历的节点x 到达节点n
+	if x == n { // 找到符合条件的一条路径
+		temp := make([]int, len(path))
+		copy(temp, path)
+		result = append(result, temp)
+		return
+	}
+	for i := 1; i <= n; i++ { // 遍历节点x链接的所有节点
+		if graph[x][i] == 1 { // 找到 x链接的节点
+			path = append(path, i)    // 遍历到的节点加入到路径中来
+			dfs(graph, i, n)          // 进入下一层递归
+			path = path[:len(path)-1] // 回溯，撤销本节点
+		}
+	}
+}
+
+func main() {
+	var n, m int
+	fmt.Scanf("%d %d", &n, &m)
+
+	// 节点编号从1到n，所以申请 n+1 这么大的数组
+	graph := make([][]int, n+1)
+	for i := range graph {
+		graph[i] = make([]int, n+1)
+	}
+
+	for i := 0; i < m; i++ {
+		var s, t int
+		fmt.Scanf("%d %d", &s, &t)
+		// 使用邻接矩阵表示无向图，1 表示 s 与 t 是相连的
+		graph[s][t] = 1
+	}
+
+	path = append(path, 1) // 无论什么路径已经是从1节点出发
+	dfs(graph, 1, n)       // 开始遍历
+
+	// 输出结果
+	if len(result) == 0 {
+		fmt.Println(-1)
+	} else {
+		for _, pa := range result {
+			for i := 0; i < len(pa)-1; i++ {
+				fmt.Print(pa[i], " ")
+			}
+			fmt.Println(pa[len(pa)-1])
+		}
+	}
+}
+```
+
+#### 邻接表写法
+```go
+package main
+
+import (
+	"fmt"
+)
+
+var result [][]int
+var path []int
+
+func dfs(graph [][]int, x, n int) {
+	if x == n {
+		temp := make([]int, len(path))
+		copy(temp, path)
+		result = append(result, temp)
+		return
+	}
+	for _, i := range graph[x] {
+		path = append(path, i)
+		dfs(graph, i, n)
+		path = path[:len(path)-1]
+	}
+}
+
+func main() {
+	var n, m int
+	fmt.Scanf("%d %d", &n, &m)
+
+	graph := make([][]int, n+1)
+	for i := 0; i <= n; i++ {
+		graph[i] = make([]int, 0)
+	}
+
+	for m > 0 {
+		var s, t int
+		fmt.Scanf("%d %d", &s, &t)
+		graph[s] = append(graph[s], t)
+		m--
+	}
+
+	path = append(path, 1)
+	dfs(graph, 1, n)
+
+	if len(result) == 0 {
+		fmt.Println(-1)
+	} else {
+		for _, pa := range result {
+			for i := 0; i < len(pa)-1; i++ {
+				fmt.Print(pa[i], " ")
+			}
+			fmt.Println(pa[len(pa)-1])
+		}
+	}
+}
+```
+
 ### Rust
 
 ### Javascript