fib.swift

final class FibTests: XCTestCase {
    class DPO1 {
        func fib(_ n: Int) -> Int {
            var dp = [0,1]
            if n < 2 {return dp[n]}
            for i in 2...n {
                dp[i&1] = dp[0] + dp[1]
            }
            return dp[n&1]
        }
    }
    func test() throws {
        let fibs = [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377 ,610]
        for i in fibs.indices {
            XCTAssertEqual(DPO1().fib(i), fibs[i])
        }
    }
}