class Solution {
public:
int maxProfit(vector<int>& prices) {
if(prices.size() < 2)return 0;
int minLop = 0,maxLop = 0;
int maxProfit = 0;
int idx = 1;
while(idx < prices.size()){
if(prices[idx] > prices[maxLop]){//find larger
maxLop = idx;
int profit = prices[maxLop] - prices[minLop];
if(profit > maxProfit){
maxProfit = profit;
}
}
else if(prices[idx] < prices[minLop]){//find smaller
minLop = idx;
maxLop = idx;
}
idx++;
}
return maxProfit;
}
};