⑨チャレンジしよう！の解答例

                
color(1) //赤
for i in 1...5 {
    for j in 1...i {
        drop(i)
    }
    for j in 6...i+5 {
        drop(j)
    }
}
color(3) //青
for i in 1...10 {
    drop(i)
}