• + 6 comments

    Here is a template for haskell.

    import Control.Monad
    
    valid :: [(Int, Int)] -> Bool
    valid f = -- code goes here --
    
    main = do
        t <- fmap (read::String->Int) getLine
        forM [1..t] (\_->do
            n <- fmap (read::String->Int) getLine
            func <- forM [1..n] (\_->do fmap ((\[a, b]->(a,b)).map (read::String->Int).words) getLine :: IO (Int, Int))
            putStrLn $ if valid func then "YES" else "NO")