Create 1006-clumsy-factorial.rs

Author: memorycancel

1006-clumsy-factorial.rs

@@ -0,0 +1,23 @@
+pub fn clumsy(n: i32) -> i32 {
+    if n == 1 { return 1 }
+    if n == 2 { return 2 }
+    let mut ret = n * (n-1) / (n-2) + n-3;
+    let mut tmp = 0;
+    for (i, num) in (1..=n-4).rev().enumerate() {
+        match i % 4 {
+            0 => { tmp = num },
+            1 => { tmp *= num },
+            2 => {
+                ret -= (tmp as f64 / num as f64).floor() as i32;
+                tmp = 0
+            },
+            3 => { ret += num },
+            _ => { },
+        }
+    }
+    ret - tmp
+}
+
+fn main() {
+    println!("{:?}", clumsy(2));
+}