GFG 169 Minimize Cost

You are given two integer arrays a and b, each of length n. You have to make the two arrays

identical (a should be a permutation of b) by performing a series of swap operations between

their elements.

1. Choose an index i (1 ≤ i ≤ n) from array a and index j (1 ≤ j ≤ n) from array b.

2. Swap a and b with the cost as min(a , b ).

Your task is to minimize the total cost of all swaps needed to make the arrays identical. If it is

impossible to make the arrays identical, return -1.

Example 1:

Input:

n = 4

a = [1, 2, 2, 2]

b = [1, 2, 4, 4]

Output: 2

Explanation:

To make a and b identical, swap the element a = 2 with the element b = 4.

The cost of this swap is min(2, 4) = 2. After the swap, a becomes [1, 2, 2, 4] and b

becomes [1, 2, 4, 2], making the arrays identical with a total cost of 2.

Example 2:

Input:

n = 2

a = [2, 4]

b = [2, 3]

Output: -1

Explanation: There is no possible swaps to make both arrays identical.

Your Task:

The task is to complete the function minCost() which takes one integer n and two arrays a and b

Constraints:

1 ≤ n ≤ 10

1 ≤ a[i],b[i] ≤ 10

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交换2个数组的元素，使得a数组跟b数组最后同构即可，就是记录两个数组元素的数量，差值必须是偶数，然后将差值放到list中，排序，用前一半即可，因为交换的成本是用的较小值。这一点还是有点不太理解。