LeetCode 121: Best Time to Buy and Sell Stock

Say you have an array for which the ith element is the price of a given stock on day i.

If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design an algorithm to find the maximum profit.

Example 1:
Input: [7, 1, 5, 3, 6, 4]
Output: 5

max. difference = 6-1 = 5 (not 7-1 = 6, as selling price needs to be larger than buying price)
Example 2:
Input: [7, 6, 4, 3, 1]
Output: 0

In this case, no transaction is done, i.e. max profit = 0.

import java.util.Scanner;

/**
 * Created by yuanxu on 17/4/12.
 */
public class DP121 {

    public static int maxProfit(int[] prices) {
        if (prices.length == 0) {
            return 0;
        }
        int max = 0;
        int curMin = prices[0];
        for (int i=1; i<prices.length; i++) {
            if (prices[i] > curMin) {
                max = (prices[i] - curMin) > max ? (prices[i] - curMin) : max;
            } else {
                curMin = prices[i];
            }
        }
        return max;
    }


    public  static void main(String args[]) {
        Scanner scanner = new Scanner(System.in);
        String inputString = scanner.nextLine();
        String stringArray[] = inputString.substring(1,inputString.length()-1).split(", ");
        int prices[] = new int[stringArray.length];
        for(int i=0; i<stringArray.length; i++) {
            prices[i] = Integer.parseInt(stringArray[i]);
        }
        System.out.println(maxProfit(prices));
    }



}