121-Best-Time-to-Buy-and-Sell-Stock.java

class Solution {
    public int maxProfit(int[] prices) {
        int min = Integer.MAX_VALUE;
        int ans = Integer.MIN_VALUE;
        for (int val: prices) {
            min = Math.min(min, val);
            ans = Math.max(ans, val - min);
        }
        return ans;
    }
}