ArrayGreedy
You are given the price of a stock on each day. Choose one day to buy and a later day to sell to maximise profit. If no profit is possible, the answer is 0.
Input
Line 1: n, the number of days. Line 2: n prices.
Output
Print the maximum profit.
Constraints
1 <= n <= 10^5 0 <= price <= 10^9
Example 1
Input
6 7 1 5 3 6 4
Output
5
Buy at 1, sell at 6 for a profit of 5.
Example 2
Input
5 7 6 4 3 1
Output
0
Prices only fall, so do not trade.