Best Time to Buy and Sell Stock-LeetCode#121

121. Best Time to Buy and Sell Stock

Say you have an array for which the i^th element is the price of a given stock on day i.
If you were only permitted to complete at most one transaction (i.e., buy one and sell one share of the stock), design an algorithm to find the maximum profit.
Note that you cannot sell a stock before you buy one.
Example 1:

Input: [7,1,5,3,6,4]
Output: 5
Explanation: Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.
             Not 7-1 = 6, as selling price needs to be larger than buying price.

Example 2:

Input: [7,6,4,3,1]
Output: 0
Explanation: In this case, no transaction is done, i.e. max profit = 0.

得到一个数组，每个数字表示第i天买入需要的价格，求出卖出获得最大利率，只能买卖一次

public class BestTimeToBuyAndSellStock {
    public int maxProfit(int[] prices) {
        if (prices.length <= 1){
            return 0;
        }
        int temp = prices[0];
        int dis = 0;
        for (int i = 1; i < prices.length; i++){
            if (prices[i] > temp) {
                dis = Math.max(dis, prices[i] - temp) ;
            } else{
                temp = prices[i];
            }
        }
        return dis;
    }
    public static void main(String[] args) {
        BestTimeToBuyAndSellStock bestTimeToBuyAndSellStock = new BestTimeToBuyAndSellStock();
        int[] a = {2,4,15,1,11};
        System.out.println(bestTimeToBuyAndSellStock.maxProfit(a));
    }
}