python3

javascript

java

Best Time to Buy and Sell Stock

You are given an array of prices where prices[i] is the price of a given stock on an 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.

### Input Format

First Parameter - number `n`

Second Parameter - array of integers of size `n`

### Output Format

Return the number.

### Example 1:
```txt
Input:
    6
    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:
```txt
Input:
    5
    7 6 4 3 1
Output:
    0
Explanation:
    In this case, no transactions are done and the max profit = 0.
```

#### Constraints:
- 1 <= prices.length <= 10^5^
- 0 <= prices[i] <= 10^4^
- Expected Time Complexity: O(n)
- Expected Space Complexity: O(1)


function solve(n, prices){
// CODE HERE
}

int solve(int n, vector<int> prices){
//CODE HERE 
}

static int solve(int n, int[] prices){
//CODE HERE 
}