# C#LeetCode刷题之#122-买卖股票的最佳时机 II（Best Time to Buy and Sell Stock II）

Say you have an array for which the ith element is the price of a given stock on day i.

Design an algorithm to find the maximum profit. You may complete as many transactions as you like (i.e., buy one and sell one share of the stock multiple times).

Note: You may not engage in multiple transactions at the same time (i.e., you must sell the stock before you buy again).

Input: [7,1,5,3,6,4]

Output: 7

Explanation: Buy on day 2 (price = 1) and sell on day 3 (price = 5), profit = 5-1 = 4.Then buy on day 4 (price = 3) and sell on day 5 (price = 6), profit = 6-3 = 3.

Input: [1,2,3,4,5]

Output: 4

Explanation: Buy on day 1 (price = 1) and sell on day 5 (price = 5), profit = 5-1 = 4.Note that you cannot buy on day 1, buy on day 2 and sell them later, as you are engaging multiple transactions at the same time.You must sell before buying again.

Input: [7,6,4,3,1]

Output: 0

Explanation: In this case, no transaction is done, i.e. max profit = 0.

```public class Program {

public static void Main(string[] args) {
int[] prices = { 7, 1, 5, 3, 6, 4 };

var res = MaxProfit(prices);
Console.WriteLine(res);

}

private static int MaxProfit(int[] prices) {
//没什么好说的，简单的贪心算法
//这里的贪心策略是只要能赚钱就卖掉
//贪心算法在某些问题中无法得到整体最优解，只能得到局部最优解
//在某些问题中总是能得到整体最优解
//具体分析在百度百科上可以查到，有兴趣的同学可以了解一下
int res = 0;
for(int i = 0; i < prices.Length - 1; i++) {
int diss = prices[i + 1] - prices[i];
if(diss > 0) {
res += diss;
}
}
return res;
}

}```

`7`