/*
 * @lc app=leetcode.cn id=121 lang=cpp
 *
 * [121] 买卖股票的最佳时机
 */

// @lc code=start
class Solution {
public:
    int maxProfit(vector<int>& prices) {
        int n = prices.size();
        vector<int> dp(2);
        dp[1] = -prices[0];
        for (int i = 1; i < n; ++i) {
            dp[0] = max(dp[0], dp[1] + prices[i]);
            dp[1] = max(dp[1], -prices[i]);
        }
        return dp[0];
    }
};
// @lc code=end