Add to List 121. Best Time to Buy and Sell Stock

class Solution {
public:
int maxProfit(vector<int>& prices) {
int maxCur = 0, maxAll = 0;
if(prices.size() <= 1) return 0;
auto i = prices.begin();
++i;
for(; i != prices.end(); ++i) {
maxCur = max(0, maxCur += *i - *(--i));
maxAll = max(maxCur, maxAll);
++i;
}
return maxAll;
}
};