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Rearrange Students

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Problem statement

In your school, two lines of students are formed A and B, with each line having exactly N students. The two lines of students will face each other. The Physical Education teacher wants the heights of all students standing across from each other to be equal. To do this, students may be swapped from one line to another. Any student in one line can be swapped with any student in the other line. Each swap counts as one operation, and each operation costs the minimum height in the swap. Reordering the students within one line has no cost. Determine the minimal cost to achieve the desired result. If it is impossible, return -1.

Function

rearrangeStudents(arrA: int[], arrB: int[]) → long

Complete the function rearrangeStudents in the editor.

The function has the following parameters:

  1. int arrA[n]: the heights of the children in line A
  2. int arrB[n]: the heights of the children in line B

Returns

long: the minimal cost to rearrange the students or -1

Examples

Example 1

arrA = [4, 2, 2, 2]arrB = [1, 4, 1, 2]return = 1

If the arrays are sorted descending, then arrA=[4, 2, 2, 2] and arrB = [4, 2, 1, 1]. Swap a 2 in arrA with a 1 in arrB for a cost of min(1, 2) = 1. This is the only swap that must occur, so the answer is 1.

Constraints

  • 1 <= n <= 2 x 10^5
  • 1 <= arrA[i], arrB[i] <= 10^9

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public long rearrangeStudents(int[] arrA, int[] arrB) {
  // write your code here
}
arrA[4, 2, 2, 2]
arrB[1, 4, 1, 2]
expected1
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