股票价格波动

/* 思路：使用Stream来处理集合的最大值和最小值查找。仍然使用HashMap来存储时间戳和价格的映射。 */

import java.util.HashMap;
import java.util.Map;

class StockPrice {
    private Map<Integer, Integer> timestampPriceMap;
    private int latestTimestamp;
    
    public StockPrice() {
        timestampPriceMap = new HashMap<>();
        latestTimestamp = 0;
    }
    
    public void update(int timestamp, int price) {
        if (timestamp >= latestTimestamp) {
            latestTimestamp = timestamp;
        }
        timestampPriceMap.put(timestamp, price);
    }
    
    public int current() {
        return timestampPriceMap.get(latestTimestamp);
    }
    
    public int maximum() {
        return timestampPriceMap.values().stream().mapToInt(v -> v).max().getAsInt();
    }
    
    public int minimum() {
        return timestampPriceMap.values().stream().mapToInt(v -> v).min().getAsInt();
    }
}