Best Time to Buy and Sell Stock

MaxProfitSellingStocks.java

import java.lang.Math;

public class Solution {
    public int maxProfit(int[] prices) {
        
        if (prices.length <= 1) return 0;
        
        int minPrice = prices[0];
        int maxSoFar = Integer.MIN_VALUE;
        int profitSoFar = Integer.MIN_VALUE;
        
        for (int i = 1; i < prices.length; i++){
            profitSoFar = prices[i] - minPrice;
            minPrice = Math.min(minPrice, prices[i]);
            maxSoFar = Math.max(profitSoFar, maxSoFar);
            
        }
        
        return Math.max(maxSoFar, 0);
    }
}

//variation, can buy and sell multiple times

public class Solution {
    public int maxProfit(int[] prices) {
        if (prices.length <= 1) return 0;
        
        int maxSoFar = 0;
        int profitCurrent = 0;
        
        for (int i = 1; i < prices.length; i++){
            profitCurrent = prices[i] - prices[i-1];
            if (profitCurrent > 0){
                maxSoFar += profitCurrent;
            }
        }
        
        return Math.max(maxSoFar, 0);
        
    }
}