Create 0207-course-schedule.rs

rust/0207-course-schedule.rs

@@ -0,0 +1,40 @@
+impl Solution {
+    pub fn can_finish(num_courses: i32, prerequisites: Vec<Vec<i32>>) -> bool {
+        let mut graph = vec![vec![]; num_courses as usize];
+        let mut visited = vec![0; num_courses as usize];
+
+        for edge in prerequisites {
+            graph[edge[0] as usize].push(edge[1] as usize);
+        }
+
+        for i in 0..num_courses as usize {
+            if !Self::dfs(i, &graph, &mut visited) {
+                return false;
+            }
+        }
+
+        true
+    }
+
+    fn dfs(i: usize, graph: &Vec<Vec<usize>>, visited: &mut Vec<i32>) -> bool {
+        if visited[i] == 1 {
+            return false;
+        }
+
+        if visited[i] == -1 {
+            return true;
+        }
+
+        visited[i] = 1;
+
+        for j in graph[i].iter() {
+            if !Self::dfs(*j, graph, visited) {
+                return false;
+            }
+        }
+
+        visited[i] = -1;
+
+        true
+    }
+}