Merge pull request neetcode-gh#1568 from razer96/207-Course-Schedule.go

go/207-Course-Schedule.go

@@ -0,0 +1,42 @@
+func canFinish(numCourses int, prerequisites [][]int) bool {
+ graph := make(map[int][]int)
+
+ for _, prer := range prerequisites {
+ graph[prer[1]] = append(graph[prer[1]], prer[0])
+ }
+
+ visitSet := make(map[int]struct{})
+
+ var dfs func(course int) bool
+
+ dfs = func(course int) bool {
+ if _, ok := visitSet[course]; ok {
+ return false
+ }
+
+ if len(graph[course]) == 0 {
+ return true
+ }
+
+ visitSet[course] = struct{}{}
+
+ for _, pre := range graph[course] {
+ if !dfs(pre) {
+ return false
+ }
+ }
+ delete(visitSet, course)
+
+ graph[course] = []int{}
+
+ return true
+ }
+
+ for i := 0; i < numCourses; i++ {
+ if !dfs(i) {
+ return false
+ }
+ }
+
+ return true
+}