Day10

509. Fibonacci Number/Solution.cs

@@ -0,0 +1,20 @@
+namespace _509._Fibonacci_Number;
+
+public class Solution
+{
+    public int Fib(int n)
+    {
+        if (n == 0)
+            return 0;
+        n--;
+        int cur0 = 0;
+        int cur1 = 1;
+        while (--n > 0)
+        {
+            int buf = cur0 + cur1;
+            cur0 = cur1;
+            cur1 = buf;
+        }
+        return cur0 + cur1;
+    }
+}