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.

Have you met this question in a real interview? 

Yes

Example

Given array [3,2,3,1,2], return 1.

 

LeetCode上的原题，请参见我之前的解法。

 

class Solution {public:    /**     * @param prices: Given an integer array     * @return: Maximum profit     */    int maxProfit(vector
       
         &prices) {        int res = 0, mn = INT_MAX;        for (int i = 0; i < prices.size(); ++i) {            mn = min(mn, prices[i]);            res = max(res, prices[i] - mn);        }        return res;    }};