# LeetCode 121. Best Time to Buy and Sell Stock: Java Solution

## Problem Statement

You are given an array for which the `ith`

element is the price of a stock on day `i`

.

Assume you can only complete at most one transaction (i.e, buy one and sell one share of the stock). Design a function to find the maximum profit that you could make.

```
Function Signature (Java):
int maxProfit(int[] prices)
Inputs:
prices = [10, 1, 5, 2, 8, 1]
Outputs:
5
We can buy at 1 and then sell at 8 => 8 - 1 = 7;
Note that the answer is not from 10 - 1, because we cannot buy at 1 and then sell at 10.
Inputs:
prices = [7, 6, 4, 3, 1]
Outputs:
0
No transaction is done - we would only lose money.
```

## TL;DR Code Solution

```
public int maxProfit(int[] prices) {
int max = 0;
int bought = Integer.MAX_VALUE;
for (int i = 0; i < prices.length; i++) {
max = Math.max(max, prices[i] - bought);
bought = Math.min(bought, prices[i]);
}
return max;
}
```