完成所有交易的初始最少钱数

// 思路：同上，利用Java Stream API实现

import java.util.*;
import java.util.stream.*;

public class Solution {
    public int minimumMoney(int[][] transactions) {
        List<int[]> gainMoney = Arrays.stream(transactions)
            .filter(t -> t[1] >= t[0])
            .sorted(Comparator.comparingInt(t -> t[0]))
            .collect(Collectors.toList());

        List<int[]> loseMoney = Arrays.stream(transactions)
            .filter(t -> t[1] < t[0])
            .sorted((a, b) -> Integer.compare(b[0] - b[1], a[0] - a[1]))
            .collect(Collectors.toList());

        int money = 0;
        int maxCost = 0;

        for (int[] transaction : gainMoney) {
            money = Math.max(money, maxCost + transaction[0]);
            maxCost = Math.max(maxCost, maxCost + transaction[0] - transaction[1]);
        }

        for (int[] transaction : loseMoney) {
            money = Math.max(money, maxCost + transaction[0]);
            maxCost = Math.max(maxCost, maxCost + transaction[0] - transaction[1]);
        }

        return money;
    }
}