Solved a0646

Author: guangsheng.li01

src/a0646_maximum_length_of_pair_chain.rs

@@ -7,8 +7,18 @@ pub struct Solution {}
 // solution impl starts here
 
 impl Solution {
-    fn add(a: i32, b: i32) -> i32 {
-        a + b
+    pub fn find_longest_chain(pairs: Vec<Vec<i32>>) -> i32 {
+        let mut pairs = pairs;
+        pairs.sort_by_key(|p| p[1]);
+        let mut t = pairs[0][1];
+        let mut count = 1;
+        for p in pairs {
+            if p[0] > t {
+                count += 1;
+                t = p[1];
+            }
+        }
+        count
     }
 }
 
@@ -22,7 +32,27 @@ mod tests {
 
     #[test]
     fn test_case0() {
-        assert_eq!(5, Solution::add(2, 3));
+        assert_eq!(
+            Solution::find_longest_chain(vec![vec![1, 2], vec![2, 3], vec![3, 4]]),
+            2
+        );
+    }
+
+    #[test]
+    fn test_case1() {
+        assert_eq!(
+            Solution::find_longest_chain(vec![
+                vec![-10, -8],
+                vec![8, 9],
+                vec![-5, 0],
+                vec![6, 10],
+                vec![-6, -4],
+                vec![1, 7],
+                vec![9, 10],
+                vec![-4, 7]
+            ]),
+            4
+        );
     }
 }
 

src/lib.rs

@@ -23,6 +23,7 @@ mod a0404_sum_of_left_leaves;
 mod a0405_convert_a_number_to_hexadecimal;
 mod a0617_merge_two_binary_trees;
 mod a0643_maximum_average_subarray_i;
+mod a0646_maximum_length_of_pair_chain;
 mod a0867_transpose_matrix;
 mod a0929_unique_email_addresses;
 mod a0931_minimum_falling_path_sum;