Best Time to Buy and Sell Stock【找出最大利润】

题目：

https://oj.leetcode.com/problems/best-time-to-buy-and-sell-stock/

Best Time to Buy and Sell Stock

  Total Accepted: 17471  Total Submissions: 56335 My Submissions

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

If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design an algorithm to find the maximum profit.

题意：

       给你一组数据。第 i 个数据代表第 i 天的股价。

     你只可以进行一次完整的交易（先买进一支股，再抛出一支股，注意顺序），求最大利润。

本质：求一个 int 数组中的最大差值变种。

算法：

算的上是贪心吧...如果这样也叫算法的话~

心情不好，水题刷着玩，难怪这么弱。

Submit Time	Status	Run Time	Language
9 minutes ago	Accepted	52 ms	cpp

code:

/**
author:free斩
Accepted	 52 ms	cpp
*/

#include 
#include 

using namespace std;

class Solution {
public:
    int maxProfit(vector &prices) {
        int len = prices.size();
        if(len <= 0) return 0;

        int minVal = prices[0];
        int maxProfit = 0;


        for(int i = 0; i < len; i++) {
            minVal = min(minVal, prices[i]);
            maxProfit = max(maxProfit, prices[i] - minVal);

        }

        return maxProfit;

    }
};

int main()
{
    vector v;
    v.push_back(3);
    v.push_back(4);
    v.push_back(1);

    Solution ss;
    int ans = ss.maxProfit(v);
    cout << ans << endl;
    return 0;
}