LeetCode 121: Best Time to Buy and Sell Stock

class Solution {
public:
	int maxProfit(vector<int>& prices) {
		int profit = 0, buy = prices[0], size = prices.size(), i;

		for (i = 1; i < size; i++) {
			profit = max(profit, prices[i] - buy);
			buy = min(buy, prices[i]);
		}

		return profit;
	}
};