20240625 Finished

src/problem/mod.rs

@@ -158,3 +158,4 @@ mod p200_number_of_islands;
 mod p130_surrounded_regions;
 mod p399_evaluate_division;
 mod p207_course_schedule;
+mod p210_course_schedule_ii;

src/problem/p210_course_schedule_ii.rs

@@ -0,0 +1,63 @@
+/**
+ * [210] Course Schedule II
+ */
+pub struct Solution {}
+
+
+// submission codes start here
+use std::collections::VecDeque;
+
+impl Solution {
+    pub fn find_order(num_courses: i32, prerequisites: Vec<Vec<i32>>) -> Vec<i32> {
+        let num = num_courses as usize;
+        let mut edges = vec![vec![];num];
+        let mut in_degs = vec![0;num];
+
+        for edge in prerequisites {
+            let (x, y) = (edge[1] as usize, edge[0] as usize);
+
+            edges[x].push(y);
+            in_degs[y] += 1;
+        }
+
+        let mut queue = VecDeque::new();
+
+        for i in 0..num {
+            if in_degs[i] == 0 {
+                queue.push_back(i);
+            }
+        }
+
+        let mut result = vec![];
+
+        while !queue.is_empty() {
+            let node = queue.pop_front().unwrap();
+            result.push(node);
+
+            for &next in &edges[node] {
+                in_degs[next] -= 1;
+
+                if in_degs[next] == 0 {
+                    queue.push_back(next);
+                }
+            }
+        }
+
+        if result.len() != num {
+            vec![]
+        } else {
+            result.iter().map(|x| *x as i32).collect()
+        }
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_210() {
+    }
+}