1. 122

best-time-to-buy-and-sell-stock-ii

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2. 算法

http://www.cnblogs.com/grandyang/p/4280803.html

此题和上面一题的不同之处在于不限制交易次数。也是一次遍历即可，只要可以赚就做交易。

3. 代码

class Solution {
public:
    int maxProfit(vector<int> &prices) {
        if (prices.empty()) return 0;
        int res = 0;
        for (int i = 1; i < prices.size(); ++i) {
            if (prices[i] - prices[i - 1] > 0) {
                res += prices[i] - prices[i - 1];
            }
        }
        return res;
    }
};