20240922 finished.

src/problem/mod.rs

@@ -243,3 +243,4 @@ mod p2332_the_latest_time_to_catch_a_bus;
 mod p2414_length_of_the_longest_alphabetical_continuous_substring;
 mod p2376_count_special_integers;
 mod p2374_node_with_highest_edge_score;
+mod p997_find_the_town_judge;

src/problem/p997_find_the_town_judge.rs

@@ -0,0 +1,62 @@
+use regex::escape;
+
+/**
+ * [997] Find the Town Judge
+ */
+pub struct Solution {}
+    
+
+// submission codes start here
+
+impl Solution {
+    pub fn find_judge(n: i32, trust: Vec<Vec<i32>>) -> i32 {
+        use std::collections::HashMap;
+        let n = n as usize;
+
+        let mut trust_map = HashMap::with_capacity(n);
+        let mut trusted_map = HashMap::with_capacity(n);
+
+        for i in 1..=n {
+            trust_map.insert(i, 0);
+        }
+
+        for i in trust {
+            let (a, b) = (i[0] as usize, i[1] as usize);
+
+            let entry = trust_map.entry(a).or_insert(0);
+            *entry += 1;
+
+            let entry = trusted_map.entry(b).or_insert(vec![]);
+            entry.push(a);
+        }
+
+        for man in trust_map.iter().filter(|p| *p.1 == 0) {
+            if let Some(people) = trusted_map.get(man.0) {
+                if people.len() == n - 1 && !people.contains(man.0) {
+                    return *man.0 as i32;
+                }
+            } else {
+                if n == 1 {
+                    return *man.0 as i32;
+                }
+            }
+        }
+
+        -1
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_997() {
+        assert_eq!(2, Solution::find_judge(2, vec![vec![1, 2]]));
+        assert_eq!(3, Solution::find_judge(3, vec![vec![1, 3], vec![2, 3]]));
+        assert_eq!(1, Solution::find_judge(1, vec![]));
+        assert_eq!(-1, Solution::find_judge(2, vec![]));
+    }
+}