LeetCode(python)——870. 优势洗牌

题目描述

给定两个大小相等的数组 A 和 B，A 相对于 B 的优势可以用满足 A[i] > B[i] 的索引 i 的数目来描述。

返回 A 的任意排列，使其相对于 B 的优势最大化。

示例 1：

输入：A = [2,7,11,15], B = [1,10,4,11]
输出：[2,11,7,15]

示例 2：

输入：A = [12,24,8,32], B = [13,25,32,11]
输出：[24,32,8,12]

提示：

1 <= A.length = B.length <= 10000
0 <= A[i] <= 10^9
0 <= B[i] <= 10^9

题目理解

代码实现

class Solution(object):
    def advantageCount(self, A, B):
        sortedA = sorted(A)
        sortedB = sorted(B)

        # assigned[b] = list of a that are assigned to beat b
        # remaining = list of a that are not assigned to any b
        assigned = {b: [] for b in B}# 创建字典 
        remaining = []

        # populate (assigned, remaining) appropriately
        # sortedB[j] is always the smallest unassigned element in B
        j = 0
        for a in sortedA:
            if a > sortedB[j]:
                assigned[sortedB[j]].append(a)
                j += 1
            else:
                remaining.append(a)

        # Reconstruct the answer from annotations (assigned, remaining)
        return [assigned[b].pop() if assigned[b] else remaining.pop()
                for b in B]