Leetcode学习笔记：#888. Fair Candy Swap_leetcode 888. fair candy swap-优快云博客

本文介绍Leetcode #888题“公平糖果交换”的解题思路与Java实现。Alice和Bob通过交换糖果棒使其总量相等，需找出双方交换的糖果棒大小。文章提供了一种使用HashSet和差值查找的高效解决方案。

Leetcode学习笔记：#888. Fair Candy Swap

Alice and Bob have candy bars of different sizes: A[i] is the size of the i-th bar of candy that Alice has, and B[j] is the size of the j-th bar of candy that Bob has.

Since they are friends, they would like to exchange one candy bar each so that after the exchange, they both have the same total amount of candy. (The total amount of candy a person has is the sum of the sizes of candy bars they have.)

Return an integer array ans where ans[0] is the size of the candy bar that Alice must exchange, and ans[1] is the size of the candy bar that Bob must exchange.

If there are multiple answers, you may return any one of them. It is guaranteed an answer exists.

实现：

public int[] fairCandySwap(int[] A, int[] B){
	int dir = (IntStream.of(A).sum() - IntStream.of(B).sum()) / 2;
	HashSet<Integer> S = new HashSet<>();
	for(int a : A) S.add(a);
	for(int b : B)
		if(S.contains(d + dif)) 
			return new int[] {b + dif, b};
	return new int[0];
}

思路：
设dif为两数组之和除以2，则找到a = b+dif即可