#### clueless coding// TODO: be smarter

Cracking the Coding Interview Elements of Programming Interviews Programming Interviews Exposed # LeetCode 121. Best Time to Buy and Sell Stock: C++ Solution

## Problem Statement

You are given an array for which the `ith` element is the price of a stock on day `i`.

If you could only complete at most one transaction (i.e, buy one and sell one share of the stock), write a function to find the maximum profit.

``````Function Signature (C++):
int maxProfit(vector<int>& prices)

Inputs:
prices = [7, 1, 5, 3, 6, 4]

Outputs:
5

We can buy at 1 and then sell at 6 => 6 - 1 = 5;

Note that the answer is not from 7 - 1, because we cannot buy at 1 and then sell at 7.

Inputs:
prices = [7, 6, 4, 3, 1]

Outputs:
0

No transaction is done - we would only lose money.
``````

## TL;DR Code Solution

``````int maxProfit(vector<int>& prices) {

int currentMin = INT_MAX;
int result = 0;

for (int i = 0; i < prices.size(); i++) {
result = max(result, prices[i] - currentMin);
currentMin = min(currentMin, prices[i]);
}

return result;

}

``````