Easy
You are given an integer array arr
. Sort the integers in the array in ascending order by the number of 1
’s in their binary representation and in case of two or more integers have the same number of 1
’s you have to sort them in ascending order.
Return the array after sorting it.
Example 1:
Input: arr = [0,1,2,3,4,5,6,7,8]
Output: [0,1,2,4,8,3,5,6,7] Explantion: [0] is the only integer with 0 bits.
[1,2,4,8] all have 1 bit.
[3,5,6] have 2 bits.
[7] has 3 bits.
The sorted array by bits is [0,1,2,4,8,3,5,6,7]
Example 2:
Input: arr = [1024,512,256,128,64,32,16,8,4,2,1]
Output: [1,2,4,8,16,32,64,128,256,512,1024] Explantion: All integers have 1 bit in the binary representation, you should just sort them in ascending order.
Constraints:
1 <= arr.length <= 500
0 <= arr[i] <= 104
class Solution {
fun sortByBits(arr: IntArray): IntArray {
val map: MutableMap<Int, MutableList<Int>> = HashMap()
for (num in arr) {
val count = Integer.bitCount(num)
map.putIfAbsent(count, ArrayList())
map[count]!!.add(num)
}
val result = IntArray(arr.size)
var i = 0
for ((_, list) in map) {
list.sort()
for (num in list) {
result[i++] = num
}
}
return result
}
}