DecompressRun-LengthEncodedList1313.kt

package easy

/*
We are given a list nums of integers representing a list compressed with run-length encoding.

Consider each adjacent pair of elements [freq, val] = [nums[2*i], nums[2*i+1]] (with i >= 0).  For each such pair, there are freq elements with value val concatenated in a sublist. Concatenate all the sublists from left to right to generate the decompressed list.

Return the decompressed list.



Example 1:

Input: nums = [1,2,3,4]
Output: [2,4,4,4]
Explanation: The first pair [1,2] means we have freq = 1 and val = 2 so we generate the array [2].
The second pair [3,4] means we have freq = 3 and val = 4 so we generate [4,4,4].
At the end the concatenation [2] + [4,4,4] is [2,4,4,4].
Example 2:

Input: nums = [1,1,2,3]
Output: [1,3,3]
 */
fun decompressRLElist(nums: IntArray): IntArray {
    val array=arrayListOf<Int>()

    for(i in nums.indices step 2)
    {
        val freq =nums[i]
        val value =nums[i+1]
        for(j in 0 until freq)
        {
            array.add(value)
        }
    }
    return array.toIntArray()
}