BestTimeToBuyAndSell.java

package array;

//	You are 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.
//	
//	 
//	
//	Example 1:
//	
//	Input: prices = [7,1,5,3,6,4]
//	Output: 5
//	Explanation: Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.
//	Note that buying on day 2 and selling on day 1 is not allowed because you must buy before you sell.
//	Example 2:
//	
//	Input: prices = [7,6,4,3,1]
//	Output: 0
//	Explanation: In this case, no transactions are done and the max profit = 0.
//	 
//	
//	Constraints:
//	
//	1 <= prices.length <= 105
//	0 <= prices[i] <= 104
//	
//	https://leetcode.com/problems/best-time-to-buy-and-sell-stock/description/
//		
	
public class BestTimeToBuyAndSell {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

	}
	
	public int maxProfit(int[] prices) {
		int n = prices.length;
		if(n < 2) {
			return 0;
		}
		int minPrice = prices[0];
		int maxProfit = 0;
		
		for(int i = 0; i < n; i++) {
			minPrice = Math.min(minPrice, prices[i]);
			maxProfit = Math.max(maxProfit, prices[i] - minPrice);
		}
		return maxProfit;
	}

}