58. 배열 만들기 3

import Foundation

func solution(_ arr:[Int], _ intervals:[[Int]]) -> [Int] {
    
    var answer : [Int] = []
    
    for i in 0...intervals.count-1 {
        
        answer += Array(arr[Int(intervals[i][0]) ... Int(intervals[i][1])])
        
    }
    
    
    return answer
}