59: Re-submit

sankichi92 · Dec 29, 2023 · fe7ea67 · fe7ea67
1 parent 16b61fa
commit fe7ea67
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/59-n-th-tribonacci-number/src/lib.rs b/59-n-th-tribonacci-number/src/lib.rs
@@ -3,7 +3,8 @@ pub fn tribonacci(n: i32) -> i32 {
         0 => 0,
         1 => 1,
         2 => 1,
-        _ => tribonacci(n - 1) + tribonacci(n - 2) + tribonacci(n - 3)
+        3 => 2,
+        _ => 2 * tribonacci(n - 1) - tribonacci(n - 4),
     }
 }
 
@@ -20,4 +21,9 @@ mod tests {
     fn case2() {
         assert_eq!(tribonacci(25), 1389537)
     }
+
+    #[test]
+    fn failed_case1() {
+        assert_eq!(tribonacci(34), 334745777)
+    }
 }