class Main {
/*
Given an array prices where prices[i] is the price of a given stock
on the ith day, you want to maximize your profit by choosing a single day
to buy one stock and choosing a different day in the future to sell that stock.
Return the maximum profit you can achieve from this transaction.
If you cannot achieve any profit, return 0.
prices = [7, 1, 5, 3, 6, 4]
output --> 5
*/
// conditonal - if less than 2 days then no profit
// min price --> first day, max price =0
// iterate prices array frpm 2day
// update min price so far
//calculate profiy sold on current day
// calculatye max profit on current day is more then return max profit
public static int maxProfit(int[] prices){
if(prices == null || prices.length < 2){
return 0;
}
int minPrice = prices[0];
int maxPrice = 0;
for(int i =1; i<prices.length; i++){
minPrice = Math.min(minPrice, prices[i]);
int profit = prices[i] - minPrice;
maxPrice= Math.max(maxPrice, profit);
}
return maxPrice;
}
public static void main(String[] args) {
int[] prices = {7,1,5,3,6,4};
int result = maxProfit(prices);
System.out.println(result);
}
}
