Fair Candy Swap
给两个整数组, 交换一对整数, 让两个整数组想加的和相等. 首先先求两个数组的和, 然后求他们的差, 这个差值就是交换两个数的差值.
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class Solution { public int[] fairCandySwap(int[] A, int[] B) { int sumA = 0; int sumB = 0; for(int a : A) sumA += a; for(int b : B) sumB += b; int diff = (sumB - sumA) / 2; Set<Integer> set = new HashSet<Integer>(); for(int i = 0 ; i < B.length; i++) { set.add(B[i]); } for(int a : A) { if(set.contains(a+diff)) return new int[]{a, a+diff}; } return null; } } |