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[LeetCode 121] Best Time to Buy and Sell Stock
Problem
You are given an array prices where prices[i] is the price of a given stock on the 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.
Example 1:
Input: prices = [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:
Input: prices = [7,6,4,3,1]
Output: 0
Explanation: In this case, no transactions are done and the max profit = 0.
Constraints:
- 1 <= prices.length <= 105
- 0 <= prices[i] <= 104
TypeScript
function maxProfit(prices: number[]): number {
if(prices.length === 0 || prices.length === 1) {
return 0;
}
let res: number = 0;
let left: number = 0, right: number = 1;
while(right < prices.length) {
if(prices[left] < prices[right]){
let profit: number = prices[right] - prices[left];
if(profit > res) {
res = profit;
}
} else {
left = right;
}
right++;
}
return res;
};