Hard
You are given an array target
of n integers. From a starting array arr
consisting of n
1’s, you may perform the following procedure :
x
be the sum of all elements currently in your array.i
, such that 0 <= i < n
and set the value of arr
at index i
to x
.Return true
if it is possible to construct the target
array from arr
, otherwise, return false
.
Example 1:
Input: target = [9,3,5]
Output: true
Explanation: Start with arr = [1, 1, 1]
[1, 1, 1], sum = 3 choose index 1
[1, 3, 1], sum = 5 choose index 2
[1, 3, 5], sum = 9 choose index 0
[9, 3, 5] Done
Example 2:
Input: target = [1,1,1,2]
Output: false
Explanation: Impossible to create target array from [1,1,1,1].
Example 3:
Input: target = [8,5]
Output: true
Constraints:
n == target.length
1 <= n <= 5 * 104
1 <= target[i] <= 109
class Solution {
fun isPossible(target: IntArray): Boolean {
var sum = target[0].toLong()
var maxIndex = 0
for (i in 1 until target.size) {
sum += target[i].toLong()
if (target[i] > target[maxIndex]) {
maxIndex = i
}
}
val remainingSum = sum - target[maxIndex]
if (target[maxIndex] == 1 || remainingSum == 1L) {
return true
}
if (remainingSum >= target[maxIndex] || remainingSum == 0L || target[maxIndex] % remainingSum == 0L) {
return false
}
target[maxIndex] %= remainingSum.toInt()
return isPossible(target)
}
}