JAVA

buy and sell stock

class Solution {
    public int maxProfit(int[] prices) {
        int minimum=Integer.MAX_VALUE;
        int maxprofit=0;
        for(int i=0;i<prices.length;i++){
            if(prices[i]<minimum) minimum=prices[i];
            else if(prices[i]-minimum>maxprofit)    maxprofit=prices[i]-minimum;
        }
        return maxprofit;
        
    }
}

buy and sell stocks

class Solution:
    def maxProfit(self, prices: List[int]) -> int:
	    if not prices:
		    return 0

	    maxProfit = 0
	    minPurchase = prices[0]
	    for i in range(1, len(prices)):		
		    maxProfit = max(maxProfit, prices[i] - minPurchase)
		    minPurchase = min(minPurchase, prices[i])
	    return maxProfit