Best Time to Buy and Sell Stock
Desicription
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.
Example 1:
代码语言：javascript复制Input: [7, 1, 5, 3, 6, 4]
Output: 5
max. difference = 6-1 = 5 (not 7-1 = 6, as selling price needs to be larger than buying price)Example 2:
代码语言：javascript复制Input: [7, 6, 4, 3, 1]
Output: 0
In this case, no transaction is done, i.e. max profit = 0.Solution
代码语言：javascript复制class Solution {
public:
int maxProfit(vector<int>& prices) {
int minn = INT_MAX;
int res = 0;
for(int i = 0; i < prices.size(); i )
minn = min(minn, prices[i]), res = max(res, prices[i] - minn);
return res;
}
};
