LeetCode in Kotlin
1589. Maximum Sum Obtained of Any Permutation
Medium
We have an array of integers, nums, and an array of requests where requests[i] = [starti, endi]. The ith request asks for the sum of nums[starti] + nums[starti + 1] + ... + nums[endi - 1] + nums[endi]. Both starti and endi are 0-indexed.
Return the maximum total sum of all requests among all permutations of nums.
Since the answer may be too large, return it modulo 109 + 7.
Example 1:
Input: nums = [1,2,3,4,5], requests = [[1,3],[0,1]]
Output: 19
Explanation: One permutation of nums is [2,1,3,4,5] with the following result:
requests[0] -> nums[1] + nums[2] + nums[3] = 1 + 3 + 4 = 8
requests[1] -> nums[0] + nums[1] = 2 + 1 = 3
Total sum: 8 + 3 = 11.
A permutation with a higher total sum is [3,5,4,2,1] with the following result:
requests[0] -> nums[1] + nums[2] + nums[3] = 5 + 4 + 2 = 11
requests[1] -> nums[0] + nums[1] = 3 + 5 = 8
Total sum: 11 + 8 = 19, which is the best that you can do.
Example 2:
Input: nums = [1,2,3,4,5,6], requests = [[0,1]]
Output: 11
Explanation: A permutation with the max total sum is [6,5,4,3,2,1] with request sums [11].
Example 3:
Input: nums = [1,2,3,4,5,10], requests = [[0,2],[1,3],[1,1]]
Output: 47
Explanation: A permutation with the max total sum is [4,10,5,3,2,1] with request sums [19,18,10].
Constraints:
n == nums.length1 <= n <= 1050 <= nums[i] <= 1051 <= requests.length <= 105requests[i].length == 20 <= starti <= endi < n
Solution
class Solution {
fun maxSumRangeQuery(nums: IntArray, requests: Array<IntArray>): Int {
nums.sort()
val l = nums.size
val tempArr = IntArray(l)
// requests[i][0] incrementing index element by 1 and for requests[i][1]+1 decrementing by 1
// this will help me get the freq of occurrence of each index of array 'nums' in
// all 'requests' intervals when I compute the sum array of tempArr.
for (request in requests) {
val a = request[0]
val b = request[1] + 1
tempArr[a]++
if (b < l) {
tempArr[b]--
}
}
var prev = 0
for (i in 0 until l) {
tempArr[i] += prev
prev = tempArr[i]
}
tempArr.sort()
var index = l - 1
var ans: Long = 0
while (index >= 0) {
if (tempArr[index] == 0) {
break
}
val x = (tempArr[index] % 1000000007).toLong()
val y = (nums[index] % 1000000007).toLong()
index--
ans += x * y
}
return (ans % 1000000007).toInt()
}
}